Income Taxes (Effective tax rate reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Federal tax	$ 30,097	$ 13,501	$ 10,783
State income taxes, net of federal tax provision (benefit)	18	29	213
Foreign income taxed at lower tax rates	(9,421)	(8,363)	(15,515)
U.S. tax impact of foreign operations	365	608	3,631
Foreign withholding taxes	3,694	866
Goodwill impairment		904
Research and development	(2,666)	(2,294)
Liability for unrecognized tax benefits	(556)	7,802	4,217
Provision-to-return adjustments	(1,925)	554	(102)
Other	753	874	1,598
Total income tax provision	$ 20,359us-gaap_IncomeTaxExpenseBenefit	$ 14,481us-gaap_IncomeTaxExpenseBenefit	$ 4,825us-gaap_IncomeTaxExpenseBenefit
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Income tax rate, Federal tax	35.00%	35.00%	35.00%
Income tax rate, State income taxes	0.00%	0.10%	0.70%
Income tax rate, Foreign income taxed at lower tax rates	(11.00%)	(21.70%)	(50.40%)
Income tax rate, U.S. tax impact of foreign operations	0.40%	1.60%	11.80%
Income tax rate, Foreign withholding taxes	4.30%	2.20%
Income tax rate, Goodwill impairment		2.30%
Income tax rate, Research and development	(3.10%)	(5.90%)
Income tax rate, Liability for unrecognized tax benefits	(0.60%)	20.20%	13.70%
Income tax rate, Provision-to-return adjustment	(2.20%)	1.40%	(0.30%)
Income tax rate, Other	0.90%	2.30%	5.20%
Income tax rate, Total	23.70%	37.50%	15.70%

The portion of the difference, between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to U.S. Tax impact of foreign operations.

No definition available.