Revision of Previously Reported Financial Information Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income	$ 61,141	$ 28,582	$ 66,102	$ 64,046
Other operating activities and non-cash items			$ (4,382)	(9,879)
Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income		29,021		68,919
Other operating activities and non-cash items				(14,752)
Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income		$ (439)		(4,873)
Other operating activities and non-cash items				$ 4,873