Condensed Consolidated Statements of Changes in Common Stockholders' Equity Statement - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
As of at Dec. 31, 2018	$ 2,916,782	$ 20,000	$ 378,837	$ 6,236,125	$ 203,829	$ (3,922,009)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income for the period	81,702			81,702
Issuance of noncontrolling interest	6,000						6,000
Net loss attributable to noncontrolling interest	0			62			(62)
Net income attributable to redeemable noncontrolling interests	(16)			(16)
Change in redemption value of redeemable noncontrolling interest	(54)		(54)
Dividends on common stock	(14,779)			(14,779)
Issuance of Class B common stock, net of restricted stock awards and forfeitures	(28)		(3,783)			3,755
Amortization of unearned stock compensation and stock option expense	1,639		1,639
Other comprehensive (loss) income, net of income taxes	8,290				8,290
Purchase of redeemable noncontrolling interest	0
As of at Mar. 31, 2019	2,999,536	20,000	376,639	6,303,094	212,119	(3,918,254)	5,938
As of at Dec. 31, 2018	4,346
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income attributable to redeemable noncontrolling interests	16
Change in redemption value of redeemable noncontrolling interests	54
Purchase of redeemable noncontrolling interest	(550)
As of at Mar. 31, 2019	3,866
As of at Dec. 31, 2019	3,326,796	20,000	381,669	6,534,427	303,295	(3,920,152)	7,557
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income for the period	(33,891)			(33,891)
Net loss attributable to noncontrolling interest	0			772			(772)
Net income attributable to redeemable noncontrolling interests	(126)			(126)
Dividends on common stock	(15,289)			(15,289)
Repurchase of Class B Common Stock	(33,610)					(33,610)
Issuance of Class B common stock, net of restricted stock awards and forfeitures	5,335					5,335
Amortization of unearned stock compensation and stock option expense	1,568		1,568
Other comprehensive (loss) income, net of income taxes	(37,943)				(37,943)
As of at Mar. 31, 2020	3,212,840	$ 20,000	$ 383,237	$ 6,485,893	$ 265,352	$ (3,948,427)	$ 6,785
As of at Dec. 31, 2019	5,655
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income attributable to redeemable noncontrolling interests	126
As of at Mar. 31, 2020	$ 5,781