Condensed Consolidated Statements of Stockholders’ Equity (Unaudited) - USD ($) $ in Thousands	Total	Treasury Stock	Add’l Paid in Capital	Accumulated Comprehensive Income	Accumulated Deficit	Series AA PREF Stock Preferred Stock	Class A CMN Stock Common Stock	Class B CMN Stock Common Stock
Beginning balance at Dec. 31, 2020	$ 1,202,768	$ (44,786)	$ 1,963,850	$ 934	$ (717,331)	$ 0	$ 87	$ 14
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash compensation	1,060		1,060
Issuance of common stock through stock awards	13,376		13,376
Exercise of stock options	5,224		5,224
Issuance of common stock through employee purchase plan	2,172		2,172
Purchase of treasury stock	(5,717)	(5,717)
Foreign currency translation adjustments	204			204
Net income	38,329				38,329
Dividends/distributions to common shareholders	(75,818)				(75,818)
Dividends, preferred stock	(91)				(91)
Ending balance at Mar. 31, 2021	1,181,507	(50,503)	1,985,682	1,138	(754,911)	0	87	14
Beginning balance at Dec. 31, 2021	1,217,089	(50,852)	2,001,399	855	(734,415)	0	88	14
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Non-cash compensation	1,405		1,405
Issuance of common stock through stock awards	30,145		30,145
Exercise of stock options	1,307		1,307
Issuance of common stock through employee purchase plan	3,589		3,589
Purchase of treasury stock	(10,446)	(10,446)
Foreign currency translation adjustments	314			314
Net income	92,151				92,151
Dividends/distributions to common shareholders	(111,602)				(111,602)
Dividends, preferred stock	(91)				(91)
Ending balance at Mar. 31, 2022	$ 1,223,861	$ (61,298)	$ 2,037,845	$ 1,169	$ (753,957)	$ 0	$ 88	$ 14