CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) shares in Thousands, $ in Thousands	Mandatory Convertible Preferred Shares Preferred Stock	Common Stock	Capital in Excess of Par Value	Accumulated Other Comprehensive Income	Retained Earnings	Treasury Shares	Non-controlling Interest	Total
Balance at the beginning of the period at Dec. 31, 2018	$ 6	$ 410	$ 3,392,937	$ (29,325)	$ 650,842	$ (1,314,020)	$ 49,476	$ 2,750,326
Balance (in shares) at Dec. 31, 2018	5,750	409,652
Increase (Decrease) in Equity
Net income (loss)					(117,709)		14,176	(103,533)
Dividends to common shareholders					(3,947)			(3,947)
Dividends to preferred shareholders					(4,313)			(4,313)
Other comprehensive income (loss), net of tax				9,338			52	9,390
Share-based compensation			8,424					8,424
Accrued distribution on redeemable noncontrolling interest in subsidiary					(5,063)			(5,063)
Other		$ 6	(1,251)					(1,245)
Other (in shares)		6,264
Balance at the end of the period at Mar. 31, 2019	$ 6	$ 416	3,400,110	(19,987)	519,810	(1,314,020)	63,704	2,650,039
Balance (in shares) at Mar. 31, 2019	5,750	415,916
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)					(391,827)		17,465	(374,362)
Dividends to common shareholders					(3,514)			(3,514)
Dividends to preferred shareholders					(3,652)			(3,652)
Repurchase of common and preferred shares	$ (1)		(12,126)			(1,731)		(13,858)
Repurchase of common and preferred shares (in shares)	(724)
Other comprehensive income (loss), net of tax				(17,218)				(17,218)
Share-based compensation			9,158					9,158
Accrued distribution on redeemable noncontrolling interest in subsidiary					(4,432)			(4,432)
Other		$ 3	(1,550)				358	(1,189)
Other (in shares)		3,268
Balance at the end 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	4,889	419,466