CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Mandatory Convertible Preferred Shares Preferred Stock	Common Stock	Capital in Excess of Par Value	Accumulated Other Comprehensive Income	Retained Earnings (Accumulated Deficit)	Treasury Shares	Non-controlling Interest	Total
Balance at the beginning of the period at Dec. 31, 2019	$ 6	$ 416	$ 3,412,972	$ (11,788)	$ (104,775)	$ (1,314,020)	$ 67,354	$ 2,050,165
Balance (in shares) at Dec. 31, 2019	5,613	8,324
Increase (Decrease) in Equity
Net income (loss)					(697,404)		38,437	(658,967)
Dividends declared to common shareholders					(3,633)			(3,633)
Dividends declared to preferred shareholders					(10,958)			(10,958)
Repurchase of shares	$ (1)		(12,126)			(1,731)		(13,858)
Repurchase of shares (in shares)	(743)
Other comprehensive income (loss), net of tax				(6,842)				(6,842)
Share-based compensation			20,170					20,170
Noncontrolling interest contributions (distributions)							(2,032)	(2,032)
Accrued distribution on redeemable noncontrolling interest in subsidiary					(13,092)			(13,092)
Other		$ 3	(1,549)				357	(1,189)
Other (in shares)		61
Balance at the end of the period at Sep. 30, 2020	$ 5	$ 419	3,419,467	(18,630)	(829,862)	(1,315,751)	104,116	1,359,764
Balance (in shares) at Sep. 30, 2020	4,870	8,385
Balance at the beginning of the period at Jun. 30, 2020	$ 5	$ 419	3,415,053	(22,188)	(664,391)	(1,315,751)	94,339	1,507,486
Balance (in shares) at Jun. 30, 2020	4,870	8,389
Increase (Decrease) in Equity
Net income (loss)					(157,465)		10,805	(146,660)
Dividends declared to preferred shareholders					(3,653)			(3,653)
Other comprehensive income (loss), net of tax				3,558				3,558
Accrued distribution on redeemable noncontrolling interest in subsidiary					(4,353)			(4,353)
Other			4,414				(1,028)	3,386
Other (in shares)		(4)
Balance at the end of the period at Sep. 30, 2020	$ 5	$ 419	3,419,467	(18,630)	(829,862)	(1,315,751)	104,116	1,359,764
Balance (in shares) at Sep. 30, 2020	4,870	8,385
Balance at the beginning of the period at Dec. 31, 2020	$ 5	$ 419	3,423,935	(11,124)	(946,100)	(1,315,751)	105,424	1,256,808
Balance (in shares) at Dec. 31, 2020	4,870	8,383
Increase (Decrease) in Equity
Net income (loss)					(455,595)		21,168	(434,427)
Deferred dividends for earned PSUs					(75)			(75)
Dividends declared to preferred shareholders					(3,653)			(3,653)
Conversion of preferred shares	$ (5)	$ 34	(34)					(5)
Conversion of preferred shares (in shares)	(4,870)	668
Issuance of warrants on common shares					(2,719)			(2,719)
Other comprehensive income (loss), net of tax				252				252
Share-based compensation			15,205					15,205
Share issuance		$ 7	12,865					12,872
Share issuance (shares)		148
Noncontrolling interest contributions (distributions)							(1,790)	(1,790)
Accrued distribution on redeemable noncontrolling interest in subsidiary					(7,088)			(7,088)
Other		$ 6	(1,563)					(1,557)
Other (in shares)		132
Balance at the end of the period at Sep. 30, 2021		$ 466	3,450,408	(10,872)	(1,415,230)	(1,315,751)	124,802	833,823
Balance (in shares) at Sep. 30, 2021		9,331
Balance at the beginning of the period at Jun. 30, 2021		$ 459	3,433,144	(8,624)	(1,290,309)	(1,315,751)	118,024	936,943
Balance (in shares) at Jun. 30, 2021		9,181
Increase (Decrease) in Equity
Net income (loss)					(122,500)		6,778	(115,722)
Deferred dividends for earned PSUs					(65)			(65)
Other comprehensive income (loss), net of tax				(2,248)				(2,248)
Share-based compensation			4,465					4,465
Share issuance		$ 7	12,865					12,872
Share issuance (shares)		148
Accrued distribution on redeemable noncontrolling interest in subsidiary					(2,356)			(2,356)
Other			(66)					(66)
Other (in shares)		2
Balance at the end of the period at Sep. 30, 2021		$ 466	$ 3,450,408	$ (10,872)	$ (1,415,230)	$ (1,315,751)	$ 124,802	$ 833,823
Balance (in shares) at Sep. 30, 2021		9,331