Income Taxes and Accounting for Uncertainty in Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes and Accounting for Uncertainty in Income Taxes
Unrecognized tax benefits if recognized, could favorably affect our effective tax rate	$ 200,000
Reversed uncertain tax position solved	34,106	$ 22,697	$ 18,646
Interest	11,000	3,000
Accrued interest and penalties	$ 26,000	$ 15,000