Income Taxes - Reconciliation of Change in Federal and State Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 909	$ 804	$ 1,102
Prior period tax positions, Increase	0	0	0
Prior period tax positions, Decrease	(251)	(37)	(449)
Current period tax positions	110	142	151
Reductions for statute of limitations expirations	0	0	0
Balance at End of Year	768	909	804
Amount That Would Impact the Effective Tax Rate if Recognized	$ 607	$ 770	$ 610