Balance Sheet Related Information (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Accumulated other comprehensive income (loss)
Cumulative foreign currency translation	$ 346	$ 24,905
Prior service cost on pension plans (net of tax benefit of $113 in 2011 and $134 in 2010)	(195)	(232)
Net actuarial loss on pension plans (net of tax benefit of $6,944 in 2011 and $1,938 in 2010)	(11,912)	(3,358)
Unrealized loss on interest rate swap agreement (net of tax benefit of $3,329 in 2011 and $2,440 in 2010)	(5,710)	(4,226)
Unrealized gain on available-for-sale securities (net of tax expense of $0 in 2011 and $1,022 in 2010)	2,503	11,847
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (14,968)	$ 28,936