Stock Repurchase Plan - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Feb. 09, 2017	Oct. 31, 2015
Equity Class Of Treasury Stock [Line Items]
Total cost of shares repurchased	$ 63,700,000	$ 34,900,000
2015 Repurchase Plan
Equity Class Of Treasury Stock [Line Items]
Authorized amount to repurchase outstanding common stock				$ 250,000,000
Total cost of shares repurchased	63,700,000
Remaining amount of authorized under 2015 Repurchase Plan	$ 29,100,000
2017 Repurchase Plan
Equity Class Of Treasury Stock [Line Items]
Authorized amount to repurchase outstanding common stock			$ 300,000,000