Common Stock and Treasury Stock (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Feb. 28, 2018
Equity [Abstract]
Amount approved for repurchase			$ 200,000,000
Shares repurchased (in shares)	1,000,000	1,000,000
Shares repurchased, value	$ 39,411,000	$ 28,881,000
Shares repurchased to date (in shares)	47,357,495
Shares repurchased to date, value	$ 651,700,000
Maximum remaining amount authorized for purchase	$ 72,700,000