Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Line Items]
Limited net operating loss carryforwards	$ 1,400,000
Accrued interest related to unrecognized tax benefits	0	$ 0
Decrease in net deferred tax asset position due to change in tax rate	15,800,000
Federal
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	135,500,000
Credit carryforwards	1,700,000
State
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	109,900,000
Credit carryforwards	$ 1,900,000