Consolidated Statement of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Cumulative Effect	Cumulative effect of accounting changes	Preferred stock	Preference stock	Common Stock	Additional Paid-in Capital	Retained earnings	Retained earnings Cumulative Effect	Retained earnings Cumulative effect of accounting changes	Accumulated other comprehensive loss	Accumulated other comprehensive loss Cumulative Effect	Accumulated other comprehensive loss Cumulative effect of accounting changes	Treasury stock
Balance at Dec. 31, 2017	$ 30,553		$ (12,207)	$ 1	$ 441	$ 323,338	$ 138,367	$ 5,074,343		$ 104,026	$ (794,940)	$ (116,233)	$ (116,233)	$ (4,710,997)
Increase (Decrease) in Stockholders' Equity
Net (loss) income	241,811							241,811
Other comprehensive income (loss)	(37,788)										(37,788)
Cash dividends
Common	(140,466)							(140,466)
Preference	(32)							(32)
Issuances of common stock	(1,071)						(37,030)							35,959
Conversions to common stock	0				(45)		(904)							949
Stock-based compensation	21,042						21,042
Balance at Dec. 31, 2018	101,842			1	396	323,338	121,475	5,279,682			(948,961)			(4,674,089)
Increase (Decrease) in Stockholders' Equity
Net (loss) income	194,609							194,609
Other comprehensive income (loss)	108,818										108,818
Cash dividends
Common	(35,353)							(35,353)
Preference	(8)							(8)
Issuances of common stock	(1,684)						(43,062)							41,378
Conversions to common stock					(130)		(2,804)							2,934
Redemption of preferred/preference stock	(277)			(1)	(266)		(10)
Stock-based compensation	23,149						23,149
Repurchase of common stock	(105,000)													(105,000)
Balance at Dec. 31, 2019	286,096	$ (21,900)		0	0	323,338	98,748	5,438,930	$ (21,900)		(840,143)			(4,734,777)
Increase (Decrease) in Stockholders' Equity
Net (loss) income	(181,544)							(181,544)
Other comprehensive income (loss)	1,012										1,012
Cash dividends
Common	(34,291)							(34,291)
Issuances of common stock	(454)						(47,722)							47,268
Stock-based compensation	17,476						17,476
Balance at Dec. 31, 2020	$ 66,395			$ 0	$ 0	$ 323,338	$ 68,502	$ 5,201,195			$ (839,131)			$ (4,687,509)