FINANCIAL INFORMATION Revenue, Initial Application Period Cumulative Effect Transition (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accrued expenses and other current liabilities	$ 39,373		$ 31,549
Accounts receivable, net of allowances of $1,164 and $11,142 at June 30, 2018 and December 31, 2017, respectively	47,703		40,134
Contract with Customer, Asset, Gross	15,544		0
Inventory, Net	(31,752)		(38,421)
Other long-term assets	10,222		10,811
Assets	253,952		234,684
Deferred Revenue, Current	(82,470)		(121,184)
Deferred Revenue, Noncurrent	(15,228)		(73,429)
Liabilities	430,826		503,254
Accumulated deficit	(1,193,791)		(1,284,703)
Stockholders' Equity Attributable to Parent	$ (176,874)		(268,570)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accrued expenses and other current liabilities			11,139
Accounts receivable, net of allowances of $1,164 and $11,142 at June 30, 2018 and December 31, 2017, respectively			21,088
Contract with Customer, Asset, Gross			6,579
Inventory, Net			(5,716)
Other long-term assets			865
Assets			22,816
Deferred Revenue, Current			(41,611)
Deferred Revenue, Noncurrent			(55,079)
Liabilities			85,551
Accumulated deficit		$ 3,800	108,367
Stockholders' Equity Attributable to Parent			108,367
Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accrued expenses and other current liabilities			42,688
Accounts receivable, net of allowances of $1,164 and $11,142 at June 30, 2018 and December 31, 2017, respectively			61,222
Contract with Customer, Asset, Gross			6,579
Inventory, Net			(32,705)
Other long-term assets			11,676
Assets			257,500
Deferred Revenue, Current			(79,573)
Deferred Revenue, Noncurrent			(18,350)
Liabilities			417,703
Accumulated deficit			(1,176,336)
Stockholders' Equity Attributable to Parent			$ (160,203)