Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member] Class A [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings [Member]	Total
Balance at beginning of period at Dec. 31, 2021	$ 91	$ 601,703	$ (1,526,860)	$ (73,896)	$ 1,911,734	$ 912,772
Stockholders' Equity [Roll Forward]
Net income	0	0	0	0	72,953	72,953
Other comprehensive loss, net of tax	0	0	0	(16,742)	0	(16,742)
Repurchase of Class A common stock (Note 6)	0	0	(20,010)	0	0	(20,010)
Exercise of employee stock options/vesting of stock awards	0	(1,503)	26,101	0	0	24,598
Stock-based compensation	0	6,149	0	0	0	6,149
Cash dividends	0	0	0	0	(38,685)	(38,685)
Balance at end of period at Jun. 30, 2022	91	606,349	(1,520,769)	(90,638)	1,946,002	941,035
Balance at beginning of period at Mar. 31, 2022	91	599,258	(1,526,778)	(69,528)	1,931,157	934,200
Stockholders' Equity [Roll Forward]
Net income	0	0	0	0	34,237	34,237
Other comprehensive loss, net of tax	0	0	0	(21,110)	0	(21,110)
Repurchase of Class A common stock (Note 6)	0	0	(10,004)	0	0	(10,004)
Exercise of employee stock options/vesting of stock awards	0	5,069	16,013	0	0	21,082
Stock-based compensation	0	2,022	0	0	0	2,022
Cash dividends	0	0	0	0	(19,392)	(19,392)
Balance at end of period at Jun. 30, 2022	91	606,349	(1,520,769)	(90,638)	1,946,002	941,035
Balance at beginning of period at Dec. 31, 2022	91	613,278	(1,569,061)	(86,509)	1,939,497	897,296
Stockholders' Equity [Roll Forward]
Net income	0	0	0	0	38,268	38,268
Other comprehensive loss, net of tax	0	0	0	(14,937)	0	(14,937)
Exercise of employee stock options/vesting of stock awards	0	(6,502)	11,284	0	0	4,782
Stock-based compensation	0	8,803	0	0	0	8,803
Cash dividends	0	0	0	0	(38,867)	(38,867)
Balance at end of period at Jun. 30, 2023	91	615,579	(1,557,777)	(101,446)	1,938,898	895,345
Balance at beginning of period at Mar. 31, 2023	91	611,483	(1,559,080)	(91,005)	1,931,481	892,970
Stockholders' Equity [Roll Forward]
Net income	0	0	0	0	26,892	26,892
Other comprehensive loss, net of tax	0	0	0	(10,441)	0	(10,441)
Exercise of employee stock options/vesting of stock awards	0	(705)	1,303	0	0	598
Stock-based compensation	0	4,801	0	0	0	4,801
Cash dividends	0	0	0	0	(19,475)	(19,475)
Balance at end of period at Jun. 30, 2023	$ 91	$ 615,579	$ (1,557,777)	$ (101,446)	$ 1,938,898	$ 895,345