Income Taxes - Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Valuation allowance	$ (21)	$ (33)	$ 13,542
Tax Credit Carryforward, Amount	200
Capital loss carryforwards and other than temporary impairment	56	2,099
Capital Loss Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Valuation Allowance	56	2,099
Expired Capital Loss Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Amount	5,900	100
Capital loss carryforwards and other than temporary impairment	$ 2,100	$ 0