Subsequent Events (Details) - Common Shares - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	1 Months Ended	6 Months Ended
	Jul. 25, 2016	Jun. 30, 2016
Subsequent Event [Line Items]
Common shares repurchased during period, Number of shares		2,400
Common shares repurchased during period, Aggregate amount		$ 272.3
Common shares repurchased during period, Average cost per share, in usd per share		$ 112.50
Subsequent Event
Subsequent Event [Line Items]
Common shares repurchased during period, Number of shares	286
Common shares repurchased during period, Aggregate amount	$ 33.1
Common shares repurchased during period, Average cost per share, in usd per share	$ 115.66