Income Taxes Income tax (Details) (USD $)	12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 Foreign Deferred Tax Assets [Member]	Dec. 31, 2011 Foreign Deferred Tax Assets [Member] Foreign Tax Authority [Member]	Dec. 31, 2010 Foreign Deferred Tax Assets [Member] Foreign Tax Authority [Member]	Dec. 31, 2012 Foreign Deferred Tax Assets [Member] UK	Dec. 31, 2011 Foreign Deferred Tax Assets [Member] UK	Dec. 31, 2010 Foreign Deferred Tax Assets [Member] UK
Operating Loss Carryforwards [Line Items]
State net operating loss carry forwards	$ 98,900,000
Foreign tax credits	2,200,000
Foreign net operating losses	20,000,000
Valuation Allowance, Deferred Tax Asset, Change in Amount					600,000	600,000	3,400,000	500,000	400,000	2,800,000
Gross unrecognized tax benefits	588,000	1,070,000	1,351,000	2,189,000
Interest and penalties realted to unrecognized tax benefits	800,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	0
Undistributed earnings of foreign subsidiaries	$ 39,700,000