INCOME TAXES (NARRATIVE) (DETAILS) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement Narrative [Line Items]
Total deferred tax assets, net				$ 82,988	$ 71,754	$ 82,988
Valuation allowances				10,139	$ 9,949	10,139	$ 10,721	$ 10,792
Net Change in Valuation Allowance			$ 100	400
Tax Credit Carryforward, Description					As of December 31, 2016, domestically, the Company had federal tax credit carry forwards in the amount of $1.8 million that if unused will expire in 2023, $0.9 million that if unused will expire in 2024, $1.7 million that if unused will expire in 2025 and $1.5 million that if unused will expire in 2026. The Company also had state tax credit carry-forwards of $0.3 million that if unused will expire between 2017 and 2023.
Cumulative Amount Foreign Earnings Invested Outside United States					$ 533,600
Income Tax Holidays Description					The Company has been granted "Tax Holidays" as an incentive to attract foreign investment by the governments of the Philippines and Costa Rica. Generally, a Tax Holiday is an agreement between the Company and a foreign government under which the Company receives certain tax benefits in that country, such as exemption from taxation on profits derived from export-related activities. In the Philippines, the Company has been granted multiple agreements with an initial period of four years and additional periods for varying years, expiring at various times between 2017 and 2019.
Income Tax Holiday Termination Date					2017 and 2019
Aggregate Effect on Income Tax Expense for Income Tax Holiday Jurisdictions					$ 12,400	$ 12,200	$ 20,200
Diluted Net Income Per Share Effect For Income Tax Holiday Jurisdictions					$ 0.27	$ 0.25	$ 0.27
Total Interest and Penalties Accrued Related to Uncertain Tax Positions Recorded in Balance Sheets				$ 709	$ 693	$ 709	$ 132
Reserve for Uncertain Tax Benefits, Net					3,500	$ 3,700
Decrease of Unrecognized Tax Benefits over Next 12 Months					3,500
Decrease in Unrecognized Tax Benefits is Reasonably Possible					800
Settlement with Taxing Authority [Member]
Income Statement Narrative [Line Items]
Tax Adjustments, Settlements, and Unusual Provisions	$ 800
Expired statute of limitations [Member]
Income Statement Narrative [Line Items]
Tax Adjustments, Settlements, and Unusual Provisions	$ 500	$ 300
State Tax Credits And Nol [Member]
Income Statement Narrative [Line Items]
Net Change in Valuation Allowance					$ 100
HONG KONG | rogenSi [Member]
Income Statement Narrative [Line Items]
Income Tax Examination Years Under Audit					2014
United States
Income Statement Narrative [Line Items]
Total deferred tax assets, net					$ 45,000
Income Tax Examination Years Under Audit					2012 through 2015
Foreign Jurisdictions [Member]
Income Statement Narrative [Line Items]
Total deferred tax assets, net					$ 8,400
Foreign Jurisdictions [Member] | Not Realizable Standard [Member]
Income Statement Narrative [Line Items]
Net Change in Valuation Allowance					$ (2,100)
Canada
Income Statement Narrative [Line Items]
Income Tax Examination Years Under Audit					2009 and 2010
Argentina [Member] | Not Realizable Standard [Member]
Income Statement Narrative [Line Items]
Net Change in Valuation Allowance					$ 1,800