Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Other comprehensive income (loss), before tax amount
Foreign currency translation, before tax amount	$ 3,878	$ 2,737
Unrealized holding gains (losses) on available-for-sale securities, before tax amount	9,983	17,783
Recognition of previously unrealized (gains) losses on available-for-sale securities included in net income (loss), before tax amount	493	1,362
Other comprehensive income (loss), before tax amount	14,354	21,882
Other comprehensive income loss tax (expense) benefit
Unrealized holding gains (losses) on available-for-sale securities, tax (expense) benefit	(3,649)	(6,498)
Recognition of previously unrealized (gains) losses on available-for-sale securities included in net income (loss), tax (expense) benefit	(180)	(498)
Other comprehensive income (loss), tax (expense) benefit	(3,829)	(6,996)
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax amount	3,878	2,737
Unrealized holding gains (losses) on available-for-sale securities, net of tax amount	6,334	11,285
Recognition of previously unrealized (gains) losses on available-for-sale securities included in net income (loss), net of tax amount	313	864
Other comprehensive income (loss), net of tax	$ 10,525	$ 14,886