Income Taxes - Loss Carryforwards and Other (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating loss carryforwards
Net deferred tax assets	$ 31,647	$ 27,890
Reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding accrued interest and penalties
Balance at beginning of year	8,929	240	$ 240
Additions based on tax positions related to current year		8,689
Additions based on tax positions related to prior years	2,726
Reductions for tax positions related to prior years	(8,689)
Reductions for settlements with tax authorities
Balance at end of year	2,966	8,929	240
Interest and penalties accrued	600	$ 700	$ 400
State
Operating loss carryforwards
Future tax benefits	3,200
Net operating loss carryforwards	55,500
Increase in valuation allowance	600
Net deferred tax assets	2,600
Maximum
Reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding accrued interest and penalties
Decrease in unrecognized tax benefits	$ 3,000