Income Taxes Income Tax Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Income Tax Contingency [Line Items]
Net interest and penalties expense	$ 99	$ 301
Accrued interest	2,229		$ 2,105
Accrued penalties	2,649		2,577
Unrecognized tax benefits related to uncertain tax positions	54,978		54,880
The amount of unrecognized tax benefits that, if recognized, would affect our effective tax rate	$ 53,670		$ 53,602