Condensed Consolidated Statements of Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Subtotal [Member]	Non-controlling Interest [Member]
Beginning balances at Dec. 31, 2018	$ 1,454,953	$ 1,777	$ 388,027	$ 1,647,959	$ (95,225)	$ (488,141)	$ 1,454,397	$ 556
Beginning balances, shares at Dec. 31, 2018		131,188				27,007
Net income (loss)	(52,248)			(52,245)			(52,245)	(3)
Other comprehensive loss	(117)				(117)		(117)
Share-based awards exercised or distributed	(24)		(4,209)			$ 4,185	(24)
Share-based awards exercised or distributed, shares		232				(232)
Stock compensation expense	2,767		2,767				2,767
Transactions with non-controlling interest	1							1
Ending balances at Mar. 31, 2019	1,405,332	$ 1,777	386,585	1,595,714	(95,342)	$ (483,956)	1,404,778	554
Ending balances, shares at Mar. 31, 2019		131,420				26,775
Beginning balances at Dec. 31, 2019	177,164	$ 1,777	400,047	357,857	(105,086)	$ (478,110)	176,485	679
Beginning balances, shares at Dec. 31, 2019		131,743				26,452
Net income (loss)	(965)			(941)			(941)	(24)
Other comprehensive loss	(38,719)				(38,719)		(38,719)
Share-based awards exercised or distributed			(5,051)			$ 5,051
Share-based awards exercised or distributed, shares		281				(281)
Stock compensation expense	1,650		1,650				1,650
Ending balances at Mar. 31, 2020	$ 139,130	$ 1,777	$ 396,646	$ 356,916	$ (143,805)	$ (473,059)	$ 138,475	$ 655
Ending balances, shares at Mar. 31, 2020		132,024				26,171