Stockholders' Equity (Details) - USD ($) shares in Thousands, $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Repurchases [Abstract]
Stock Repurchase Shares Authorized	5,400
Treasury Stock, Shares, Acquired	1,500	0	1,400
Payments of Dividends	$ 6.5	$ 6.6	$ 6.6

Number of shares that have been repurchased during the period and are being held in treasury.

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration