Income Taxes - Additional Disclosures (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Contingency [Line Items]
Unrecognized tax benefits	$ 25,135,000	$ 16,041,000	$ 7,156,000	$ 20,150,000
Unrecognized tax benefits, recorded as liabilities	15,693,000	8,593,000
Unrecognized tax benefits which could be realized within the next 12 months, minimum	0
Unrecognized tax benefits which could be realized within the next 12 months, maximum	6,300,000
Unrecognized tax benefits, income tax penalties and interest accrued	2,000,000	1,400,000
Balance Sheet Location Other Current Liabilities [Member]
Income Tax Contingency [Line Items]
Unrecognized tax benefits	0	258,000
Balance Sheet Location Noncurrent Liabilities [Member]
Income Tax Contingency [Line Items]
Unrecognized tax benefits	$ 15,693,000	$ 8,335,000