Accumulated Other Comprehensive Income (Reclassifications Out Of Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Revenues	$ 99,407	$ 92,574
Other income (expense), net	373	(306)
Cost of revenues	(52,720)	(48,392)
Total before tax	11,064	6,166
Estimated tax expense	(2,638)	(2,304)
Net of estimated tax	8,426	3,862
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net of estimated tax	515
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Foreign Exchange Contract [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Revenues	329
Cost of revenues	(43)
Total before tax	286
Estimated tax expense	(104)
Net of estimated tax	182
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net	523
Total before tax	523
Estimated tax expense	(190)
Net of estimated tax	$ 333