Income Taxes Income Tax Provision Included in Other Income Expense on Consolidated Statement of Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Federal	$ 132	$ 305	$ 190
State	341	35	284
Federal	0	0	0
State	93	(45)	(14)
Provision for income taxes	$ 566	$ 295	$ 460