Income Taxes - Schedule of Deferred Tax Expense (Benefit) Allocated Between Operations and Equity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Income Tax Expense Benefit Continuing Operations [Abstract]
Equity	$ 746	$ 260	$ 320
Operations	(1,276)	126	1,086
Deferred tax expense (benefit) from operations and equity	$ (530)	$ 386	$ 1,406