Shareholders' Equity - Narrative (Details) - Common Shares - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 17, 2016	Sep. 14, 2015	Aug. 24, 2015
Class of Stock [Line Items]
Stock repurchase program, authorized amount				$ 100,000,000.0
Stock repurchase program, additional authorized amount		$ 150,000,000	$ 100,000,000.0
Number of shares repurchased (in shares)	983,789
Weighted average price per share of shares repurchased (in dollars per share)	$ 25.94