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 (income) 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, 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	138,897
Other comprehensive (loss) income, net of income taxes	(3,805)
As of at Jun. 30, 2019	3,038,854	20,000	378,255	6,352,787	200,024	(3,918,254)	6,042
As of at Dec. 31, 2018	4,346
As of at Jun. 30, 2019	3,876
As of at Mar. 31, 2019	2,999,536	20,000	376,639	6,303,094	212,119	(3,918,254)	5,938
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income for the period	57,195			57,195
Net loss (income) attributable to noncontrolling interest	0			(104)			104
Net income attributable to redeemable noncontrolling interests	(10)			(10)
Dividends on common stock	(7,388)			(7,388)
Amortization of unearned stock compensation and stock option expense	1,616		1,616
Other comprehensive (loss) income, net of income taxes	(12,095)				(12,095)
As of at Jun. 30, 2019	3,038,854	20,000	378,255	6,352,787	200,024	(3,918,254)	6,042
As of at Mar. 31, 2019	3,866
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income attributable to redeemable noncontrolling interests	10
As of at Jun. 30, 2019	3,876
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 (income) 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
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	(15,029)
Other comprehensive (loss) income, net of income taxes	(20,875)
As of at Jun. 30, 2020	3,213,416	20,000	384,804	6,497,166	282,420	(3,977,722)	6,748
As of at Dec. 31, 2019	5,655
As of at Jun. 30, 2020	11,831
As of at Mar. 31, 2020	3,212,840	20,000	383,237	6,485,893	265,352	(3,948,427)	6,785
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income for the period	18,862			18,862
Net loss (income) attributable to noncontrolling interest	0			37			(37)
Acquisition of redeemable noncontrolling interest	0
Net income attributable to redeemable noncontrolling interests	(45)			(45)
Dividends on common stock	(7,581)			(7,581)
Repurchase of Class B Common Stock	(29,295)					(29,295)
Amortization of unearned stock compensation and stock option expense	1,567		1,567
Other comprehensive (loss) income, net of income taxes	17,068				17,068
As of at Jun. 30, 2020	3,213,416	$ 20,000	$ 384,804	$ 6,497,166	$ 282,420	$ (3,977,722)	$ 6,748
As of at Mar. 31, 2020	5,781
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income attributable to redeemable noncontrolling interests	45
Acquisition of redeemable noncontrolling interest	6,005
As of at Jun. 30, 2020	$ 11,831