| AQR Capital Management, LLC | 
                    0.49% | 
                    26 Mar 2019 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.59% | 
                    1 Mar 2019 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.69% | 
                    14 Feb 2019 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.79% | 
                    29 Jan 2019 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.80% | 
                    7 Jan 2019 | 
                
        
                
                    | MCP (Switzerland) S.a.r.l. | 
                    0.00% | 
                    19 Dec 2018 | 
                
        
                
                    | MCP (Switzerland) S.a.r.l. | 
                    0.72% | 
                    18 Dec 2018 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.70% | 
                    7 Dec 2018 | 
                
        
                
                    | Millennium International Management LP | 
                    0.00% | 
                    30 Nov 2018 | 
                
        
                
                    | Millennium International Management LP | 
                    0.62% | 
                    23 Nov 2018 | 
                
        
                
                    | Millennium International Management LP | 
                    0.50% | 
                    16 Nov 2018 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.60% | 
                    12 Nov 2018 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.50% | 
                    12 Oct 2018 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.47% | 
                    12 Jun 2018 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.58% | 
                    31 May 2018 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.68% | 
                    3 May 2018 | 
                
        
                
                    | BlackRock Institutional Trust Company, National Association | 
                    0.47% | 
                    30 Apr 2018 | 
                
        
                
                    | BlackRock Institutional Trust Company, National Association | 
                    0.59% | 
                    16 Apr 2018 | 
                
        
                
                    | BlackRock Institutional Trust Company, National Association | 
                    0.69% | 
                    27 Mar 2018 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.78% | 
                    22 Mar 2018 | 
                
        
                
                    | BlackRock Institutional Trust Company, National Association | 
                    0.79% | 
                    5 Mar 2018 | 
                
        
                
                    | BlackRock Institutional Trust Company, National Association | 
                    0.80% | 
                    1 Mar 2018 | 
                
        
                
                    | BlackRock Institutional Trust Company, National Association | 
                    0.70% | 
                    22 Feb 2018 | 
                
        
                
                    | BlackRock Institutional Trust Company, National Association | 
                    0.60% | 
                    7 Feb 2018 | 
                
        
                
                    | BlackRock Institutional Trust Company, National Association | 
                    0.50% | 
                    5 Jan 2018 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.89% | 
                    28 Dec 2017 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.90% | 
                    18 Dec 2017 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.80% | 
                    1 Dec 2017 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.70% | 
                    17 Nov 2017 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.69% | 
                    19 Oct 2017 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.70% | 
                    21 Jul 2017 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.69% | 
                    22 Jun 2017 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.70% | 
                    11 May 2017 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.60% | 
                    20 Apr 2017 | 
                
        
                
                    | AQR Capital Management, LLC | 
                    0.50% | 
                    3 Apr 2017 | 
                
        
                
                    | Marshall Wace LLP | 
                    0.48% | 
                    30 Sep 2016 | 
                
        
                
                    | Marshall Wace LLP | 
                    0.50% | 
                    29 Sep 2016 | 
                
        
                
                    | JPMorgan Asset Management (UK) Ltd | 
                    0.38% | 
                    9 Oct 2015 | 
                
        
                
                    | BlackRock Investment Management (UK) Limited | 
                    0.49% | 
                    8 Oct 2015 | 
                
        
                
                    | JPMorgan Asset Management (UK) Ltd | 
                    0.51% | 
                    8 Oct 2015 | 
                
        
                
                    | BlackRock Investment Management (UK) Limited | 
                    0.50% | 
                    8 Sep 2015 | 
                
        
                
                    | JPMorgan Asset Management (UK) Ltd | 
                    0.63% | 
                    2 Sep 2015 | 
                
        
                
                    | JPMorgan Asset Management (UK) Ltd | 
                    0.51% | 
                    28 Aug 2015 |