Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Income Taxes
Expected future taxable income to fully realize the deferred tax assets	$ 80,480
Change in net deferred tax assets attributable to other comprehensive income	500
Goodwill	3,000
Domestic taxable income	141,660	141,368
Unremitted earnings of non-US subsidiaries	234,000
Income tax on the repatriation of all foreign earnings	70,860
Non-US Subsidiary Cash and Cash Equivalents	37,000
Percentage of pre-tax earnings from a country which does not impose a corporate income tax	21.00%
Minimum percentage used to measure tax benefit of uncertain tax position	50.00%
Reconciliation of the beginning and ending amounts of total unrecognized tax benefits
Balance at the beginning of the period	3,271	5,506
Gross increase related to current year tax positions		(2,235)
Settlements	(3,271)
Balance at the end of the period		3,271
Interest expenses on income tax contingencies	144
Accrued interest on income tax contingencies	$ 452	$ 817