Accounting Policies (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Cash and Cash Equivalents, at Carrying Value	$ 267,986,000	$ 184,055,000	$ 545,225,000	$ 316,473,000
Cash and Cash Equivalents [Line Items]
Net Income (Loss) Attributable to Parent	$ 18,467,000	$ 14,832,000
Weighted Average Number of Shares Outstanding, Basic	19,624,000	19,387,000
Weighted Average Number of Shares Outstanding, Diluted	20,511,000	20,171,000
Earnings Per Share, Basic	$ 0.94	$ 0.77
Earnings Per Share, Diluted	$ 0.90	$ 0.74
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 268,002,000	$ 184,071,000	545,259,000	316,489,000
Restricted Stock Units (RSUs)
Cash and Cash Equivalents [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	650,000	589,000
Performance Shares
Cash and Cash Equivalents [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	237,000	195,000
Other Noncurrent Assets [Member]
Accounting Policies [Abstract]
Restricted Cash	$ 16,000	$ 16,000	34,000	16,000
Cash and Cash Equivalents [Line Items]
Restricted Cash	$ 16,000	$ 16,000	$ 34,000	$ 16,000