Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member] Class A [Member]	Additional Paid-in Capital [Member]	Treasury Stock, at Cost [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings [Member]	Total
Balance at beginning of period at Dec. 31, 2020	$ 91	$ 579,801	$ (1,461,593)	$ (64,768)	$ 1,840,740	$ 894,271
Stockholders' Equity [Roll Forward]
Net income	0	0	0	0	147,266	147,266
Other comprehensive loss, net of tax	0	0	0	(9,128)	0	(9,128)
Repurchase of Class A common stock (Note 8)	0	0	(80,420)	0	0	(80,420)
Exercise of employee stock options/vesting of stock awards	0	(1,292)	15,153	0	0	13,861
Stock-based compensation	0	23,194	0	0	0	23,194
Cash dividends	0	0	0	0	(76,272)	(76,272)
Balance at end 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	104,778	104,778
Other comprehensive loss, net of tax	0	0	0	(12,613)	0	(12,613)
Repurchase of Class A common stock (Note 8)	0	0	(70,045)	0	0	(70,045)
Exercise of employee stock options/vesting of stock awards	0	(792)	27,844	0	0	27,052
Stock-based compensation	0	12,367	0	0	0	12,367
Cash dividends	0	0	0	0	(77,015)	(77,015)
Balance at end 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	8,595	8,595
Other comprehensive loss, net of tax	0	0	0	(13,497)	0	(13,497)
Repurchase of Class A common stock (Note 8)	0	0	(13,011)	0	0	(13,011)
Exercise of employee stock options/vesting of stock awards	0	(7,071)	11,632	0	0	4,561
Stock-based compensation	0	15,646	0	0	0	15,646
Cash dividends	0	0	0	0	(77,622)	(77,622)
Balance at end of period at Dec. 31, 2023	$ 91	$ 621,853	$ (1,570,440)	$ (100,006)	$ 1,870,470	$ 821,968