Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
	Mar. 16, 2016	Mar. 31, 2016	Mar. 31, 2015
Stockholders Equity Note [Line Items]
Dividends declared and paid per share (usd per share)	$ 0.45	$ 0.45	$ 0.45
Dividend equivalents paid		$ 2.0	$ 1.6
Common Stock
Stockholders Equity Note [Line Items]
Repurchased shares for award (shares)		303,035	307,007
Average repurchase price of shares for award (usd per share)		$ 25.37	$ 34.40
Restricted Stock Units
Stockholders Equity Note [Line Items]
Restricted stock units vested and issued as common stock (shares)		784,060	731,251