Income Taxes Income Tax Contingencies (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Income Tax Contingency [Line Items]
Net interest and penalties expense	$ 168,000	$ (22,000)	$ 339,000	$ 265,000
Accrued interest	3,251,000		3,251,000		3,095,000
Accrued penalties	3,009,000		3,009,000		3,030,000
Unrecognized tax benefits related to uncertain tax positions	26,853,000		26,853,000		26,433,000
The amount of unrecognized tax benefits that, if recognized, would affect our effective tax rate	26,141,000		26,141,000		25,852,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Change, Next Twelve Months	$ (1,300,000)		$ (1,300,000)