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	416,198
Increase (Decrease) in Equity
Net income (loss)					(539,939)		27,632	(512,307)
Dividends declared to common shareholders					(3,633)			(3,633)
Dividends declared to preferred shareholders					(7,305)			(7,305)
Repurchase of shares	$ (1)		(12,127)			(1,731)		(13,859)
Repurchase of shares (in shares)	(743)
Other comprehensive income (loss), net of tax				(10,400)				(10,400)
Share-based compensation			15,757					15,757
Noncontrolling interest contributions (distributions)							(1,004)	(1,004)
Accrued distribution on redeemable noncontrolling interest in subsidiary					(8,739)			(8,739)
Other		$ 3	(1,549)				357	(1,189)
Other (in shares)		(407,809)
Balance at the end 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
Balance at the beginning of the period at Mar. 31, 2020	$ 5	$ 419	3,408,454	(29,006)	(508,200)	(1,315,751)	85,177	1,641,098
Balance (in shares) at Mar. 31, 2020	4,870	419,466
Increase (Decrease) in Equity
Net income (loss)					(148,112)		10,167	(137,945)
Dividends declared to common shareholders					(119)			(119)
Dividends declared to preferred shareholders					(3,653)			(3,653)
Other comprehensive income (loss), net of tax				6,818				6,818
Accrued distribution on redeemable noncontrolling interest in subsidiary					(4,307)			(4,307)
Other			6,599				(1,005)	5,594
Other (in shares)		(411,077)
Balance at the end 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
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)					(333,095)		14,390	(318,705)
Deferred dividends for earned PSUs					(10)			(10)
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				2,500				2,500
Share-based compensation			10,740					10,740
Noncontrolling interest contributions (distributions)							(1,790)	(1,790)
Accrued distribution on redeemable noncontrolling interest in subsidiary					(4,732)			(4,732)
Other		$ 6	(1,497)					(1,491)
Other (in shares)		130
Balance at the end 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
Balance at the beginning of the period at Mar. 31, 2021	$ 5	$ 417	3,429,089	(10,756)	(1,089,251)	(1,315,751)	114,201	1,127,954
Balance (in shares) at Mar. 31, 2021	4,870	8,503
Increase (Decrease) in Equity
Net income (loss)					(196,009)		5,614	(190,395)
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				2,132				2,132
Share-based compensation			3,965					3,965
Noncontrolling interest contributions (distributions)							(1,791)	(1,791)
Accrued distribution on redeemable noncontrolling interest in subsidiary					(2,330)			(2,330)
Other		$ 8	124					132
Other (in shares)		10
Balance at the end 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