LONG TERM DEBT AND CREDIT AGREEMENT (Details) - USD ($) $ in Thousands				3 Months Ended		6 Months Ended
	Feb. 26, 2016	Jun. 15, 2015	Jun. 09, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Term Loan, net of unamortized debt issuance costs of $4,616 at June 30, 2016				$ 94,134		$ 94,134		$ 0
Notes, net of unamortized original issue discount and debt issuance costs of $26,304 at June 30, 2016 and $29,050 at December 31, 2015, respectively				98,696		98,696		95,950
Credit Agreement				0		0		5,000
Total debt				192,830		192,830		100,950
Less: current portion				5,000		5,000		5,000
Total long-term debt				187,830		187,830		95,950
Interest Expense				4,769	$ 915	9,000	$ 1,253
Capped Call Transaction Costs						$ 0	$ (10,125)
Convertible Debt [Member]
Notes, net of unamortized original issue discount and debt issuance costs of $26,304 at June 30, 2016 and $29,050 at December 31, 2015, respectively		$ 96,700
Debt Instrument, Interest Rate, Effective Percentage		7.66%
Debt Instrument, Interest Rate, Stated Percentage		2.00%
Debt Instrument, Convertible, Terms of Conversion Feature						The Notes are convertible into cash, shares of the Company’s common stock or a combination of cash and shares of common stock, at the Company’s election, based on an initial conversion rate, subject to adjustment, of 45.5840 shares per $1,000 principal amount of Notes, which is equal to an initial conversion price of $21.94 per share. Prior to December 15, 2019, the Notes are convertible only in the following circumstances: (1) during any calendar quarter commencing after September 30, 2015, if the last reported sale price of the Company’s common stock is greater than or equal to 130% of the applicable conversion price for at least 20 trading days during a period of 30 consecutive trading days ending on the last trading day of the preceding calendar quarter; (2) during the five business day period after any five consecutive trading day period (the “Measurement Period”) in which the trading price per $1,000 principal amount of notes for each trading day in the Measurement Period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on such trading day; or (3) upon the occurrence of specified corporate transactions. On or after December 15, 2019 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert their Notes at any time, regardless of the foregoing circumstances. The Company may not redeem the Notes prior to their maturity, which means that the Company is not required to redeem or retire the Notes periodically.
Principal amount of Notes		$ 125,000
Debt Issuance Costs, Gross		4,700
Net Proceeds from Issuance of Convertible Notes Payable		120,300
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt		28,300
Interest Expense						$ 4,000
Convertible Notes unamortized issue discount and debt issuance costs				26,304		26,304		29,050
Convertible Debt [Member] | Debt [Member]
Allocation of issuance costs		3,600
Convertible Debt [Member] | Equity [Member]
Allocation of issuance costs		$ 1,100
Call Option [Member]
Debt Instrument, Call Feature			The Capped Call has a strike price of $21.94 and a cap price of $26.00 and is exercisable by the Company when and if the Notes are converted.
Capped Call Transaction Costs			$ 10,100
Cerberus Business Finance LLC [Member]
Debt Instrument, Interest Rate Terms	Interest accrues on outstanding borrowings under the Credit Facility and the Term Loan at a rate of either the LIBOR Rate (as defined in the Financing Agreement) plus 6.75% or a Reference Rate (as defined in the Financing Agreement) plus 5.75%, at the option of the Company. The Company must also pay to the Lenders, on a monthly basis, an unused line fee at a rate of 0.5% per annum.
Debt Instrument, Collateral	The Company granted a security interest on substantially all of its assets to secure the obligations under the Credit Facility and the Term Loan.
Debt Instrument, Covenant Description	The Financing Agreement contains customary representations and warranties, covenants, mandatory prepayments, and events of default under which the Company’s payment obligations may be accelerated.  The Financing Agreement includes covenants requiring the Company to maintain a Leverage Ratio (defined as the ratio of (a) consolidated total funded indebtedness to (b) consolidated Adjusted EBITDA) of no greater than 4.35:1.00 for the four quarters ending June 30, 2016, 5.40:1.00 for the four quarters ending September 30, 2016, 4.20:1.00 for the four quarters ending December 31, 2016 and thereafter declining over time from 3.50:1.00 to 2.50:1.00.  The Financing Agreement also restricts the Company from making capital expenditures in excess of $20,000,000 in any fiscal year. As of June 30, 2016 the Company was in compliance with these covenants.
Debt Instrument, Restrictive Covenants	The Financing Agreement contains restrictive covenants that are customary for an agreement of this kind, including, for example, covenants that restrict the Company from incurring additional indebtedness, granting liens, making investments and restricted payments, making acquisitions, paying dividends and engaging in transactions with affiliates.
Cerberus Business Finance LLC [Member] | Long-term Debt [Member]
Unamortized Debt Issuance Expense				4,616		4,616		$ 0
Total long-term debt	$ 100,000			100,000		100,000
Debt Instrument, Payment Terms	The Company may prepay all or any portion of the Term Loan prior to its stated maturity, subject to the payment of certain fees based on the amount repaid. The Term Loan requires quarterly principal payments of $1.25 million, which commenced in June 2016. The Term Loan also requires the Company to use 50% of excess cash, as defined in the Financing Agreement, to repay outstanding principal of the loans under the Financing Agreement.
Interest Expense, Long-term Debt				$ 2,000		$ 2,700
Cerberus Business Finance LLC [Member] | Line of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 5,000
KeyBank [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 35,000