Common Stock Stock Repurchase (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Jan. 14, 2020	Apr. 30, 2019
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount						$ 525,000,000	$ 200,000,000
Payments for Repurchase of Common Stock				$ 47,694,000	$ 23,819,000
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Payments for Repurchase of Common Stock				$ 47,694,000	$ 23,819,000
Treasury Stock, Common [Member]
Equity, Class of Treasury Stock [Line Items]
Stock Repurchased During Period, Shares	661,000	598,000	1,266,000	1,300,000	1,300,000
Payments for Repurchase of Common Stock				$ 48,600,000	$ 23,800,000
Treasury Stock remaining to be repurchased	$ (298,200,000)			(298,200,000)
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Payments for Repurchase of Common Stock				$ 48,600,000	$ 23,800,000