Unaudited Condensed Consolidated Statements of Stockholders' Deficit - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Common Stock 5.75% Convertible Notes	Additional Paid-in Capital	Additional Paid-in Capital 5.75% Convertible Notes	Additional Paid-in Capital 1.50% Convertible Notes	Retained Earnings	Noncontrolling Interest	AOCI Attributable to Parent	Treasury Stock
Beginning Balance at Dec. 31, 2017		$ 9		$ 1,044,599			$ (223,718)	$ 23,444	$ (51,280)	$ (844,030)
Beginning Balance (in shares) at Dec. 31, 2017		9,016
Shares issued on vesting of restricted stock (in shares)		29
Shares issued on conversion of 5.75% Convertible Notes	$ 12,694		$ 1		$ 12,693
Shares issued on conversion of 5.75% Convertible Notes (in shares)			1,104
Write-off of equity component of 1.50% Convertible Notes						$ (23,250)
Cumulative effect of accounting change for adoption								1,176
Cumulative effect of accounting change for adoption | ASC 606							16,540
Cumulative effect of accounting change for adoption | ASU 2016-01							(3,177)		3,177
Foreign currency translation				(22)					(2,780)
Elimination of non-controlling interest related to the acquisition of additional interest in Hydraulic joint venture				2,097				(2,097)
Change in redemption value of redeemable non-controlling interest							995
Compensation expense in connection with restricted stock				1,518
Tax benefit related to amortization of convertible notes' discount				35
Payments from non-controlling interest holders, net of imputed interest								195
Net (loss) income	(44,522)						(51,670)	7,148
Distributions to joint ventures								(5,760)
Shares repurchased on vesting of restricted stock										(146)
Ending Balance (in shares) at Jun. 30, 2018		10,149
Ending Balance at Jun. 30, 2018	(94,303)	$ 10		1,037,670			(261,030)	24,106	(50,883)	(844,176)
Beginning Balance at Mar. 31, 2018		$ 10		1,031,171			(182,105)	25,495	(45,342)	(844,055)
Beginning Balance (in shares) at Mar. 31, 2018		9,682
Shares issued on vesting of restricted stock (in shares)		4
Shares issued on conversion of 5.75% Convertible Notes					3,947
Shares issued on conversion of 5.75% Convertible Notes (in shares)			463
Foreign currency translation				(44)					(5,541)
Elimination of non-controlling interest related to the acquisition of additional interest in Hydraulic joint venture				2,097				(2,097)
Change in redemption value of redeemable non-controlling interest							504
Compensation expense in connection with restricted stock				499
Net (loss) income							(79,429)	4,291
Distributions to joint ventures								(3,583)
Shares repurchased on vesting of restricted stock										(121)
Ending Balance (in shares) at Jun. 30, 2018		10,149
Ending Balance at Jun. 30, 2018	(94,303)	$ 10		1,037,670			(261,030)	24,106	(50,883)	(844,176)
Beginning Balance at Dec. 31, 2018	(145,735)	$ 11		1,037,372			(312,796)	26,999	(53,068)	(844,253)
Beginning Balance (in shares) at Dec. 31, 2018		11,162
Shares issued on vesting of restricted stock (in shares)		95
Shares issued on conversion of 5.75% Convertible Notes	6,183		$ 4		6,179
Shares issued on conversion of 5.75% Convertible Notes (in shares)			3,671
Foreign currency translation				(17)					(603)
Change in redemption value of redeemable non-controlling interest				1,586
Compensation expense in connection with restricted stock				398
Reclass from redeemable NCI								(856)
Net (loss) income	24,751						19,216	4,599
Distributions to joint ventures								(8,130)
Shares repurchased on vesting of restricted stock										(81)
Ending Balance (in shares) at Jun. 30, 2019		14,928
Ending Balance at Jun. 30, 2019	(123,440)	$ 15		1,045,518			(293,580)	22,612	(53,671)	(844,334)
Beginning Balance at Mar. 31, 2019		$ 12		1,039,474			(294,460)	31,614	(54,792)	(844,309)
Beginning Balance (in shares) at Mar. 31, 2019		12,207
Shares issued on vesting of restricted stock (in shares)		8
Shares issued on conversion of 5.75% Convertible Notes			$ 3		$ 4,179
Shares issued on conversion of 5.75% Convertible Notes (in shares)			2,713
Foreign currency translation				21					1,121
Change in redemption value of redeemable non-controlling interest				1,586			(391)
Compensation expense in connection with restricted stock				258
Reclass from redeemable NCI								(4,759)
Net (loss) income							1,271	1,238
Distributions to joint ventures								(5,481)
Shares repurchased on vesting of restricted stock										(25)
Ending Balance (in shares) at Jun. 30, 2019		14,928
Ending Balance at Jun. 30, 2019	$ (123,440)	$ 15		$ 1,045,518			$ (293,580)	$ 22,612	$ (53,671)	$ (844,334)