Shareholders' Equity - Share Repurchase (Details) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 21, 2015
Class of Stock [Line Items]
Total price from repurchase of common shares	$ 96,098,000
Class A common shares
Class of Stock [Line Items]
Repurchase of Class A common stock, authorized amount (up to)			$ 300,000,000
Average price per share of Class A common shares (in USD per share)	$ 15.44	$ 15.76
Total price from repurchase of common shares	$ 96,000,000	$ 53,700,000
Remaining repurchase authorization	$ 146,700,000
Common Stock | Class A common shares
Class of Stock [Line Items]
Repurchases of Class A common shares (in shares)	6,215,656	3,400,000
Total price from repurchase of common shares	$ 62,000