Accumulated Other Comprehensive Income (Reclassification out of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTableTextBlock [Line Items]
Interest and other income (expense), net	$ (4,576)	$ (2,747)	$ (14,109)	$ (2,657)
Income Tax Expense (Benefit)	7,105	7,880	24,428	25,880
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax	12		9
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	0		88
Other Comprehensive Income Loss Reclassification Adjustments Total Net of Tax	12		97
Accumulated Translation Adjustment [Member]
ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTableTextBlock [Line Items]
Interest and other income (expense), net	0		116
Income Tax Expense (Benefit)	0		(28)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTableTextBlock [Line Items]
Interest and other income (expense), net	18		14
Income Tax Expense (Benefit)	$ (6)		$ (5)