LONG-TERM DEBT AND CREDIT AGREEMENT Debt Disclosurre (Details) - USD ($) $ in Thousands						3 Months Ended		6 Months Ended
	May 10, 2018	Feb. 08, 2018	Dec. 15, 2017	Mar. 14, 2017	Feb. 26, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Nov. 09, 2017	Jun. 15, 2015
Debt Instrument, Periodic Payment, Principal						$ 700		$ 700
Term Loan, net of unamortized debt issuance costs of $3,444 at June 30, 2017 and $4,042 at December 31, 2016						123,153		123,153		$ 102,751
Notes, net of unamortized original issue discount and debt issuance costs of $20,449 at June 30, 2017 and $23,413 at December 31, 2016, respectively						107,371		107,371		105,974
Other Long-term Debt						1,537		1,537		1,679
Total debt						232,061		232,061		210,404
Short-term debt						1,400		1,400		5,906
Long-term Debt						230,661		230,661		204,498
Line of Credit, Current						0		0
Interest Expense						6,278	$ 3,918	11,637	$ 8,764
Convertible Debt Retired		2,000	2,000
Convertible Debt Issued		123,000,000										125,000,000
Extinguishment of Debt, Amount		$ 2,000	$ 2,000
Repayments of Debt		$ 1,700	$ 1,700
Convertible Notes unamortized issue discount and debt issuance costs						16,538		16,538
Long-term Debt, Maturities, Repayments of Principal in Year Two						1,407		1,407
Long-term Debt, Maturities, Repayments of Principal in Year Three						123,372		123,372
Long-term Debt, Maturities, Repayments of Principal in Year Four						4,933		4,933
Long-term Debt, Maturities, Repayments of Principal in Year Five						6,537		6,537
Long-term Debt, Maturities, Repayments of Principal after Year Five						111,650		111,650
Total debt						248,599		248,599
Other Debt Obligations [Member]
Debt Instrument, Periodic Payment, Principal						62		62
Short-term debt						125		125
Long-term Debt						1,412		1,412
Convertible Notes unamortized issue discount and debt issuance costs						0		0
Long-term Debt, Maturities, Repayments of Principal in Year Two						132		132
Long-term Debt, Maturities, Repayments of Principal in Year Three						141		141
Long-term Debt, Maturities, Repayments of Principal in Year Four						152		152
Long-term Debt, Maturities, Repayments of Principal in Year Five						162		162
Long-term Debt, Maturities, Repayments of Principal after Year Five						888		888
Total debt						1,537		1,537
Cerberus Business Finance LLC [Member]
Debt Instrument, Periodic Payment, Principal						638		638
Short-term debt						1,275		1,275
Long-term Debt						121,878		121,878
Convertible Notes unamortized issue discount and debt issuance costs						2,909		2,909
Long-term Debt, Maturities, Repayments of Principal in Year Two						1,275		1,275
Long-term Debt, Maturities, Repayments of Principal in Year Three						2,231		2,231
Long-term Debt, Maturities, Repayments of Principal in Year Four						4,781		4,781
Long-term Debt, Maturities, Repayments of Principal in Year Five						6,375		6,375
Long-term Debt, Maturities, Repayments of Principal after Year Five						110,762		110,762
Total debt						126,062		126,062
Convertible Debt [Member]
Debt Instrument, Periodic Payment, Principal						0		0
Short-term debt						0		0
Long-term Debt						107,371		107,371
Long-term Debt, Gross												$ 125,000
Debt Instrument, Interest Rate, Stated Percentage												2.00%
Interest Expense						2,200		4,400
Convertible Notes unamortized issue discount and debt issuance costs						13,629		13,629		17,026
Long-term Debt, Maturities, Repayments of Principal in Year Two						0		0
Long-term Debt, Maturities, Repayments of Principal in Year Three						121,000		121,000
Long-term Debt, Maturities, Repayments of Principal in Year Four						0		0
Long-term Debt, Maturities, Repayments of Principal in Year Five						0		0
Long-term Debt, Maturities, Repayments of Principal after Year Five						0		0
Total debt						121,000		121,000
Cerberus Business Finance LLC [Member]
Debt Instrument, Collateral					We granted a security interest on substantially all of our assets to secure the obligations under the Term Loan and the Credit Facility.
Debt Instrument, Covenant Description	On May 10, 2018, we entered into an amendment to the Financing Agreement, which extended the maturity of the Financing Agreement to May 2023, and increased the Term Loan by $22.7 million and the amount available under the Credit Facility by $12.5 million. Under the terms of the amendment, aggregate quarterly principal repayments beginning September 30, 2018 through June 30, 2020 will be $318,750, then from July 1, 2020 through June 30, 2021 equal to $796,875, finally from July 1, 2021 through May 10, 2023 equal to $1,593,750. Following the amendment effective date, interest accrues on outstanding borrowings under the Term Loan and Credit Facility (each as defined in the Financing Agreement) at a rate of either the LIBOR Rate (as defined in the Financing Agreement) plus 6.625% or a Reference Rate (as defined in the Financing Agreement) plus 5.625%, at our option. The amendment modified the covenant requiring us to maintain a Leverage Ratio (defined to mean the ratio of (a) the sum of indebtedness under the Term Loan and Credit Facility, capitalized leases and non-cash collateralized letters of credit to (b) consolidated EBITDA) of no greater than 3.00:1.00 for the four quarters ended June 30, 2018 through December 31, 2018, 2.50:1.00 for the four quarters ending March 31, 2019 through December 31, 2019, 2.25:1.00 for the four quarters ending March 31, 2020 through March 31, 2021, 2.00:1.00 for the four quarters ending June 30, 2021 through December 31, 2022, respectively, and thereafter declining to 1.50:1.00.			The Financing Agreement contains customary representations and warranties, covenants, mandatory prepayments, and events of default under which our payment obligations may be accelerated.
additional long term debt											$ 15,000
Cerberus Business Finance LLC [Member] | Line of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 22,500				$ 5,000
Cerberus Business Finance LLC [Member] | Long-term Debt [Member]
Unamortized Debt Issuance Expense						2,909		2,909		$ 3,499
Long-term Debt					$ 100,000
Debt Instrument, Payment Terms					The Term Loan requires us to use 50% of excess cash flow, as defined in the Financing Agreement, to repay outstanding principal of the loans under the Financing Agreement.
Interest Expense, Long-term Debt						$ 2,700		$ 5,000
Cerberus Business Finance LLC [Member] | Line of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity					$ 5,000