Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions			3 Months Ended
	Apr. 13, 2018	Feb. 27, 2018	Mar. 31, 2018	Mar. 31, 2017	Feb. 25, 2016
Common stock dividends paid			$ 59,400,000	$ 59,400,000
Dividends paid per common share (in dollars per share)		$ 0.63
Stock repurchase program, authorized amount					$ 200,000,000
Repurchases of common stock under stock repurchase program			0
Common stock repurchase authorization amount available			$ 193,000,000
Subsequent Event
Common stock dividends paid	$ 59,400,000