CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss) (AOCI)	Non-controlling Interests
Balance as of at Dec. 31, 2015	$ 357,971	$ 47	$ (55,509)	$ 3,563,848	$ (3,165,321)	$ 40	$ 14,866
Balance as of (in shares) at Dec. 31, 2015		46,763,000	(5,988,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-based compensation expense related to stock appreciation rights (SARs) and stock options	118			118
Equity-based compensation related to deferred stock units (DSUs)	267			267
Equity-based compensation related to restricted stock (RS)	9,439			9,439
Issuance of RS, net of forfeitures primarily related to satisfying tax withholdings	(1,558)			(1,558)
Issuance of RS, net of forfeitures primarily related to satisfying tax withholdings (in shares)		(261,000)
Exercise of SARs and stock options, net of forfeitures related to satisfying tax withholdings	(12)			(12)
Exercise of SARs and stock options, net of forfeitures related to satisfying tax withholdings (in shares)		2,000
Impact of redeemable noncontrolling interests accretion	(4,103)			(4,103)
Impact of subsidiary equity transactions	4,453			4,314		(41)	180
Repurchase of common stock	$ (9,533)		$ (9,533)
Repurchase of common stock (in shares)	(1,010,000)		(1,010,000)
Net income (loss)	$ (39,777)				(37,146)		(2,631)
Balance as of at Sep. 30, 2016	317,265	$ 47	$ (65,042)	3,572,313	(3,202,467)	(1)	12,415
Balance as of (in shares) at Sep. 30, 2016		46,504,000	(6,998,000)
Balance as of at Dec. 31, 2016	365,484	$ 47	$ (129,774)	3,578,204	(3,095,236)	99	12,144
Balance as of (in shares) at Dec. 31, 2016		46,523,000	(11,586,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-based compensation expense related to stock appreciation rights (SARs) and stock options	30			30
Equity-based compensation related to deferred stock units (DSUs)	222			222
Equity-based compensation related to restricted stock (RS)	9,243			9,243
Issuance of RS, net of forfeitures primarily related to satisfying tax withholdings	(2,896)			(2,896)
Issuance of RS, net of forfeitures primarily related to satisfying tax withholdings (in shares)		(39,000)
Exercise of SARs and stock options, net of forfeitures related to satisfying tax withholdings	(1)			(1)
Impact of redeemable noncontrolling interests accretion	(103)			(103)
Impact of subsidiary equity transactions	2,360			2,531		(115)	(56)
Repurchase of common stock	$ (30,434)		$ (30,434)
Repurchase of common stock (in shares)	(2,175,268)		(2,176,000)
Net income (loss)	$ (24,569)				(23,014)		(1,555)
Balance as of at Sep. 30, 2017	$ 319,336	$ 47	$ (160,208)	$ 3,587,230	$ (3,118,250)	$ (16)	$ 10,533
Balance as of (in shares) at Sep. 30, 2017		46,484,000	(13,762,000)