Balance Sheet Related Information (Details 4) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Accrued liabilities
Bonus	$ 9,752	[1]	$ 8,213	[1]
Employee benefits and related costs	10,161	[1]	8,698	[1]
Dividends payable	5,698	[1]	5,612	[1]
Other	33,641	[1]	33,263	[1]
Accrued liabilities	$ 59,252	[1]	$ 55,786	[1]

[1] Restated