Stockholders' Equity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Treasury stock purchase plan	$ 100.0
Treasury stock purchase plan remaining available	$ 100.0
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	67,041	80,186	26,307
Payment, Tax Withholding, Share-based Payment Arrangement	$ 12.9	$ 18.6	$ 6.3
Treasury Stock, Common, Shares	209	850	408