Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Stockholders' Equity Note [Abstract]
Dividends							$ 36.8	$ 25.2
Aggregate number of shares repurchased during the period (in shares)							1,481,369
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	700,000						700,000
Shares repurchased under the program (in shares)							1,254,210
Authorized to repurchased additional shares under repurchase program (in shares)	1,056,945						1,056,945
Shares withheld for tax withholding obligations for the vesting of restricted stock awards (in shares)							227,159
Dividends declared per share of common stock (in dollars per share)	$ 0.30	$ 0.30	$ 0.30	$ 0.20	$ 0.20	$ 0.20