CONSOLDATED STATEMENTS OF STOCKHOLDERS' DEFICIT Statement - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]
Balances at beginning of period at Dec. 31, 2017	$ (268,570)	$ 423	$ 1,035,808	$ (1,284,703)	$ (17,672)	$ (2,426)
Balances at beginning of period (in shares) at Dec. 31, 2017		42,339			(983)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	104,550			104,550
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	(491)		(3,649)		$ 3,158
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures					127
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	703		703
Net Income (Loss) Attributable to Parent	(8,949)			(8,949)
Other Comprehensive Income (Loss), Net of Tax	1,148					1,148
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt	(22)		(22)
Capped Call Transaction Cost Reimbursement	2		2
Balances at end of period at Mar. 31, 2018	(171,629)	$ 423	1,032,842	(1,189,102)	$ (14,514)	(1,278)
Balances at end of period (in shares) at Mar. 31, 2018		42,339			(856)
Balances at beginning of period at Dec. 31, 2017	(268,570)	$ 423	1,035,808	(1,284,703)	$ (17,672)	(2,426)
Balances at beginning of period (in shares) at Dec. 31, 2017		42,339			(983)
Net Income (Loss) Attributable to Parent	(17,455)
Balances at end of period at Jun. 30, 2018	(176,874)	$ 423	1,028,334	(1,193,791)	$ (8,358)	(3,482)
Balances at end of period (in shares) at Jun. 30, 2018		42,339			(617)
Balances at beginning of period at Mar. 31, 2018	(171,629)	$ 423	1,032,842	(1,189,102)	$ (14,514)	(1,278)
Balances at beginning of period (in shares) at Mar. 31, 2018		42,339			(856)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	3,817			3,817
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	96		(6,060)		$ 6,156
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures					239
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	1,552		1,552
Net Income (Loss) Attributable to Parent	(8,506)			(8,506)
Other Comprehensive Income (Loss), Net of Tax	(2,204)					(2,204)
Balances at end of period at Jun. 30, 2018	(176,874)	$ 423	1,028,334	(1,193,791)	$ (8,358)	(3,482)
Balances at end of period (in shares) at Jun. 30, 2018		42,339			(617)
Balances at beginning of period at Dec. 31, 2018	(166,661)	$ 423	1,028,924	(1,187,010)	$ (5,231)	(3,767)
Balances at beginning of period (in shares) at Dec. 31, 2018		42,339			(391)
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	(1,381)		(6,612)		$ 5,231
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures					391
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	1,738		1,738
Net Income (Loss) Attributable to Parent	(213)			(213)
Other Comprehensive Income (Loss), Net of Tax	(548)					(548)
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt	(23)		(23)
Capped Call Transaction Cost Reimbursement	1		1
Balances at end of period at Mar. 31, 2019	(167,087)	$ 423	1,024,028	(1,187,223)	$ 0	(4,315)
Balances at end of period (in shares) at Mar. 31, 2019		42,339			0
Balances at beginning of period at Dec. 31, 2018	(166,661)	$ 423	1,028,924	(1,187,010)	$ (5,231)	(3,767)
Balances at beginning of period (in shares) at Dec. 31, 2018		42,339			(391)
Net Income (Loss) Attributable to Parent	(10,936)
Balances at end of period at Jun. 30, 2019	(175,823)	$ 427	1,025,301	(1,197,946)	$ 0	(3,605)
Balances at end of period (in shares) at Jun. 30, 2019		42,720			0
Balances at beginning of period at Mar. 31, 2019	(167,087)	$ 423	1,024,028	(1,187,223)	$ 0	(4,315)
Balances at beginning of period (in shares) at Mar. 31, 2019		42,339			0
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	(200)		(204)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		381
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	2,005		2,005
Net Income (Loss) Attributable to Parent	(10,723)			(10,723)
Other Comprehensive Income (Loss), Net of Tax	710					710
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt	(554)		(554)
Capped Call Transaction Cost Reimbursement	26		26
Balances at end of period at Jun. 30, 2019	$ (175,823)	$ 427	$ 1,025,301	$ (1,197,946)	$ 0	$ (3,605)
Balances at end of period (in shares) at Jun. 30, 2019		42,720			0