STOCKHOLDERS' EQUITY (Details) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 6 Months Ended | | | |
Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014 | Jul. 31, 2015 | Jun. 08, 2015 | Dec. 31, 2014 |
Stock Repurchase Program, Authorized Amount | | | | | | $ 9,000 | |
Stock Repurchase Program, Number of Shares Authorized to be Repurchased | 480,601 | | 480,601 | | 586,825 | | |
Accrued Liabilities, Current | $ 38,047 | | $ 38,047 | | | | $ 32,353 |
Allocated Share-based Compensation Expense | 2,882 | $ 2,136 | 5,344 | $ 3,398 | | | |
Stock Repurchase Program, Remaining Authorized Repurchase Amount | $ 1,400 | | $ 1,400 | | | | |
Employee Stock Option [Member] | | | | | | | |
Share Based Compensation Arrangement By Share Based Payment Award Time Based Options Outstanding Number | 5,226,863 | | 5,226,863 | | | | 5,564,111 |
Share Based Compensation Arrangement By Share Based Payment Award Performance Based Options Outstanding Number | 0 | | 0 | | | | 0 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number | 5,226,863 | | 5,226,863 | | | | 5,564,111 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price | $ 11 | | $ 11 | | | | $ 11.20 |
Share Based Compensation Arrangement by Share Based Payment Award, Time Based Options, Grants in Period, Net of Forfeitures | | | 0 | | | | |
Share Based Compensation Arrangement by Share Based Payment Award, Performance Based Options, Grants in Period, Net of Forfeitures | | | 0 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures | | | 0 | | | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price | | | $ 0 | | | | |
Share Based Compensation Arrangement By Share Based Payment Award, Time Based Options, Exercises in Period | | | (196,486) | | | | |
Share Based Compensation Arrangement By Share Based Payment Award, Performance Based Options, Exercises in Period | | | 0 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period | | | (196,486) | | | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price | | | $ 11.64 | | | | |
Share Based Compensation Arrangement By Share Based Payment Award, Time Based Options, Forfeitures and Expirations in Period | | | (140,762) | | | | |
Share Based Compensation Arrangement By Share Based Payment Award, Performance Based Options, Forfeitures and Expirations in Period | | | 0 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period | | | (140,762) | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price | | | $ 17.98 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term | | | 4 years 142 days | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $ 20,155 | | $ 20,155 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | 5,099,932 | | 5,099,932 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price | $ 11.08 | | $ 11.08 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term | | | 4 years 128 days | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value | $ 19,443 | | $ 19,443 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number | 3,815,010 | | 3,815,010 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price | $ 12.17 | | $ 12.17 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term | | | 3 years 336 days | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value | $ 12,375 | | $ 12,375 | | | | |
Restricted Stock Units (RSUs) [Member] | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Time Based Equity Instruments Other than Options, Nonvested, Number | 642,791 | | 642,791 | | | | 811,880 |
Share-based Compensation Arrangement by Share-based Payment Award, Performance Based Equity Instruments Other than Options, Nonvested, Number | 308,670 | | 308,670 | | | | 0 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 951,461 | | 951,461 | | | | 811,880 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ 13.46 | | $ 13.46 | | | | $ 10.01 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms | | | 339 days | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Non-vested Restricted Stock Aggregate Intrinsic Value | $ 12,683 | | $ 12,683 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Time Based Equity Instruments Other than Options, Grants in Period | | | 374,195 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Performance Based Equity Instruments Other than Options, Grants in Period | | | 347,295 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | 721,490 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | | | $ 15.19 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Time Based Equity Instruments Other than Options, Vested in Period | | | (333,012) | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Performance Based Equity Instruments Other than Options, Vested in Period | | | 0 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | | | (333,012) | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value | | | $ 10.18 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Time Based Equity Instruments Other than Options, Forfeited in Period | | | (210,272) | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Performance Based Equity Instruments Other than Options, Forfeited in Period | | | (38,625) | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period | | | (248,897) | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | | | $ 11.62 | | | | |
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expected to Vest Number | 864,317 | | 864,317 | | | | |
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expected To Vest Weighted Average Grant Date Fair Value | $ 13.44 | | $ 13.44 | | | | |
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expected to Vest Weighted Average Remaining Contractual Term | | | 325 days | | | | |
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expected To Vest Intrinsic Value | $ 11,521 | | $ 11,521 | | | | |
Cost of Products Revenues [Member] | | | | | | | |
Allocated Share-based Compensation Expense | 40 | 65 | 135 | 141 | | | |
Cost of Services Revenues [Member] | | | | | | | |
Allocated Share-based Compensation Expense | 175 | 98 | 334 | 175 | | | |
Research and Development Expense [Member] | | | | | | | |
Allocated Share-based Compensation Expense | 46 | 113 | 152 | 240 | | | |
Selling and Marketing Expense [Member] | | | | | | | |
Allocated Share-based Compensation Expense | 683 | 642 | 1,373 | 934 | | | |
General and Administrative Expense [Member] | | | | | | | |
Allocated Share-based Compensation Expense | $ 1,938 | $ 1,218 | $ 3,350 | $ 1,908 | | | |
Repurchase Agreements [Member] | | | | | | | |
Stock Repurchase Program, Authorized Amount | | | | | | $ 8,000 | |