Consolidated Statements of Changes in Stockholders' Equity (unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in-Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Common Stock in Treasury [Member]	Total	Cumulative Effect Adjustment for ASU Implementation [Member] Common Stock [Member]	Cumulative Effect Adjustment for ASU Implementation [Member] Additional Paid-in-Capital [Member]	Cumulative Effect Adjustment for ASU Implementation [Member] Retained Earnings [Member]	Cumulative Effect Adjustment for ASU Implementation [Member] Accumulated Other Comprehensive (Loss) Income [Member]	Cumulative Effect Adjustment for ASU Implementation [Member] Common Stock in Treasury [Member]	Cumulative Effect Adjustment for ASU Implementation [Member]
Balance at Dec. 31, 2021	$ 497	$ 576,976	$ 856,203	$ (23,344)	$ (159,879)	$ 1,250,453
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	0	39,126	0	0	39,126
Cash dividends	0	0	(12,083)	0	0	(12,083)
Purchase of treasury shares	0	0	0	0	(8,152)	(8,152)
Net issuance of shares to employee and other stock plans	0	(2,074)	0	0	539	(1,535)
Stock-based compensation	0	2,472	0	0	0	2,472
Other comprehensive income (loss)	0	0	0	(68,031)	0	(68,031)
Balance at Mar. 31, 2022	497	577,374	883,246	(91,375)	(167,492)	1,202,250
Balance at Dec. 31, 2022	497	577,853	958,433	(190,034)	(173,195)	1,173,554
Balance (ASU 2022-02 [Member]) at Dec. 31, 2022							$ 0	$ 0	$ 502	$ 0	$ 0	$ 502
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	0	33,658	0	0	33,658
Cash dividends	0	0	(12,871)	0	0	(12,871)
Net issuance of shares to employee and other stock plans	0	(2,366)	0	0	601	(1,765)
Stock-based compensation	0	2,465	0	0	0	2,465
Other comprehensive income (loss)	0	0	0	16,116	0	16,116
Balance at Mar. 31, 2023	$ 497	$ 577,952	$ 979,722	$ (173,918)	$ (172,594)	$ 1,211,659