Stockholders' Equity - Schedule of Changes in Stockholders' Equity (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Balance	$ 751,233	$ 690,756	$ 746,961	$ 714,551
Net income	20,312	13,656	38,663	24,268
Other comprehensive income (loss)	432	(164)	3,212	(11,287)
Equity compensation	2,888	2,518	6,163	6,344
Exercise of stock options	71		158	37
Net payments for stock issuances and buybacks	(785)	974	(18,365)	(23,024)
Dividends declared	(2,640)	(2,637)	(5,281)	(5,273)
Balance	$ 771,511	705,103	$ 771,511	705,103
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)	18,859	18,827	18,910	18,868
Balance	$ 23	$ 23	$ 23	$ 23
Exercise of stock options (in shares)	3		6	1
Issuance of shares pursuant to vesting of restricted stock units (in shares)	20	22	173	291
Net payments for stock issuances and buybacks (in shares)	(22)		(229)	(311)
Balance (in shares)	18,860	18,849	18,860	18,849
Balance	$ 23	$ 23	$ 23	$ 23
Additional Paid-in Capital
Balance	372,420	350,658	369,058	346,795
Equity compensation	2,888	2,518	6,163	6,344
Exercise of stock options	71		158	37
Net payments for stock issuances and buybacks	1,243	1,024	1,243	1,024
Balance	376,622	354,200	376,622	354,200
Retained Earnings
Balance	604,441	552,303	588,731	544,840
Net income	20,312	13,656	38,663	24,268
Dividends declared	(2,640)	(2,637)	(5,281)	(5,273)
Balance	$ 622,113	563,322	$ 622,113	563,322
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)	4,602	4,289	4,395	3,978
Balance	$ (214,325)	$ (188,961)	$ (196,745)	$ (164,963)
Net payments for stock issuances and buybacks (in shares)	22		229	311
Net payments for stock issuances and buybacks	$ (2,028)	$ (50)	$ (19,608)	$ (24,048)
Balance (in shares)	4,624	4,289	4,624	4,289
Balance	$ (216,353)	$ (189,011)	$ (216,353)	$ (189,011)
Accumulated Other Comprehensive Loss
Balance	(11,326)	(23,267)	(14,106)	(12,144)
Other comprehensive income (loss)	432	(164)	3,212	(11,287)
Balance	$ (10,894)	$ (23,431)	$ (10,894)	$ (23,431)