Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0000927003 (http://www.sec.gov/CIK)

Income Tax Disclosure [Abstract]	Period [Axis]
	2016-01-01 - 2016-12-31
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]	The geographic distribution of pretax income from continuing operations is as follows:     Years Ended December 31,     2016   2015   2014 Domestic   $ 13,776   $ 13,237   $ 16,735 Foreign   114,300   92,205   69,270     $ 128,076   $ 105,442   $ 86,005
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	Significant deferred tax assets and liabilities consist of the following:     Years Ended December 31,     2016   2015 Deferred tax assets         Stock based compensation   $ 2,281   $ 3,716 Net operating loss and tax credit carryforwards   36,145   49,374 Pension obligation   2,338   3,662 Excess and obsolete inventory   3,031   3,692 Deferred revenue   11,998   12,423 Vacation accrual   932   750 Restructuring   75   83 Bad debt reserve   121   114 Employee bonuses and commissions   1,908   1,191 Unrealized gain/loss   733   1,506 Warranty reserve   63   91 Other   1,700   899 Deferred tax assets   61,325   77,501 Less: Valuation allowance   (26,120 )   (37,208 ) Net deferred tax assets   35,205   40,293 Deferred tax liabilities         Depreciation and amortization   2,266   3,875 Foreign other   1,538   1,050 Other   212   260 Deferred tax liabilities   4,016   5,185 Net deferred tax assets   $ 31,189   $ 35,108
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	The following reconciles our effective tax rate on income from continuing operations to the federal statutory rate of 35%:     Years Ended December 31,     2016   2015   2014 Income taxes per federal statutory rate   $ 44,826   $ 37,498   $ 29,786 State income taxes, net of federal deduction   963   1,204   135 Change in valuation allowance   (85 )   6,503   12 Stock based compensation   1,117   (166 )   (112 ) Executive compensation   103   —   751 Domestic production activity benefit   (144 )   —   (124 ) Tax effect of foreign operations   (31,651 )   (22,495 )   (12,081 ) Tax credits   (4,495 )   (969 )   (2,208 ) Other permanent items, net   494   385   351     $ 11,128   $ 21,960   $ 16,510
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The provision for income taxes from continuing operations is summarized as follows:     Years Ended December 31,     2016   2015   2014 Current:             Federal   $ 3,187   $ 5,823   $ 6,436 State   351   335   481 Foreign   3,081   5,950   4,312 Total current provision   $ 6,619   $ 12,108   $ 11,229 Deferred:             Federal   $ 3,110   $ 569   $ 832 State   1,564   870   587 Foreign   (165 )   8,413   3,862 Total deferred provision   4,509   9,852   5,281 Total provision for income taxes   $ 11,128   $ 21,960   $ 16,510
Summary of Income Tax Contingencies [Table Text Block]	Years Ended December 31,     2016   2015   2014 Balance at beginning of period   $ 10,049   $ 8,001   $ 5,523 Additions based on tax positions taken during a prior period   104   433   136 Additions based on tax positions taken during the current period   2,318   3,413   3,757 Reductions related to a lapse of applicable statute of limitations   (1,070 )   (1,798 )   (1,415 ) Balance at end of period   $ 11,401   $ 10,049   $ 8,001