Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Summary of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period	$ (73,767)	$ (89,425)
Period Change	11,430	15,658
Balance at the end of the period	(62,337)	(73,767)
Pension Liability
Summary of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period	(3,836)	1,859
Period Change	(1,546)	(5,695)
Balance at the end of the period	(5,382)	(3,836)
Net Unrealized Gains (Losses) From Marketable Securities
Summary of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period	3,102	212
Period Change	1,605	2,890
Balance at the end of the period	4,707	3,102
Net Unrealized Gains (Losses) From Hedges
Summary of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period	(15,556)	5,362
Period Change	21,269	(20,918)
Balance at the end of the period	5,713	(15,556)
Foreign Currency Translation Adjustment
Summary of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period	(57,477)	(96,858)
Period Change	(9,898)	39,381
Balance at the end of the period	$ (67,375)	$ (57,477)