Stockholders' Equity - Schedule of Changes in Stockholders' Equity (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Balance	$ 771,511	$ 705,103	$ 746,961	$ 714,551
Net income	20,390	17,871	59,053	42,139
Other comprehensive income (loss)	(1,971)	3,671	1,241	(7,616)
Equity compensation	3,593	3,128	9,756	9,472
Exercise of stock options			158	37
Net payments for stock issuances and buybacks	(330)	(223)	(18,695)	(23,247)
Dividends declared	(2,641)	(2,639)	(7,922)	(7,912)
Balance	$ 790,552	726,911	$ 790,552	726,911
Cumulative-Effect Adjustments for Adoption of Accounting Principle | Revision of Prior Period, Adjustment
Balance		$ (513)		$ (513)
Accounting Standards Update Extensible List				us-gaap:AccountingStandardsUpdate201613Member
Common Stock
Balance (in shares)	18,860	18,849	18,910	18,868
Balance	$ 23	$ 23	$ 23	$ 23
Exercise of stock options (in shares)			6	1
Issuance of shares pursuant to vesting of restricted stock units (in shares)	13	12	186	303
Net payments for stock issuances and buybacks (in shares)	(3)	(3)	(232)	(314)
Balance (in shares)	18,870	18,858	18,870	18,858
Balance	$ 23	$ 23	$ 23	$ 23
Additional Paid-in Capital
Balance	376,622	354,200	369,058	346,795
Equity compensation	3,593	3,128	9,756	9,472
Exercise of stock options			158	37
Net payments for stock issuances and buybacks			1,243	1,024
Balance	380,215	357,328	380,215	357,328
Retained Earnings
Balance	622,113	563,322	588,731	544,840
Net income	20,390	17,871	59,053	42,139
Dividends declared	(2,641)	(2,639)	(7,922)	(7,912)
Balance	$ 639,862	578,554	$ 639,862	578,554
Retained Earnings | Cumulative-Effect Adjustments for Adoption of Accounting Principle | Revision of Prior Period, Adjustment
Balance		$ (513)		$ (513)
Accounting Standards Update Extensible List				us-gaap:AccountingStandardsUpdate201613Member
Treasury Stock
Balance (in shares)	4,624	4,289	4,395	3,978
Balance	$ (216,353)	$ (189,011)	$ (196,745)	$ (164,963)
Net payments for stock issuances and buybacks (in shares)	3	3	232	314
Net payments for stock issuances and buybacks	$ (330)	$ (223)	$ (19,938)	$ (24,271)
Balance (in shares)	4,627	4,292	4,627	4,292
Balance	$ (216,683)	$ (189,234)	$ (216,683)	$ (189,234)
Accumulated Other Comprehensive Loss
Balance	(10,894)	(23,431)	(14,106)	(12,144)
Other comprehensive income (loss)	(1,971)	3,671	1,241	(7,616)
Balance	$ (12,865)	$ (19,760)	$ (12,865)	$ (19,760)