Servicing Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Servicing assets:
Balance at beginning of period	$ 7,978	$ 9,867	$ 8,520	$ 10,218
Addition related to sale of SBA loans	344	406	659	841
Amortization	(755)	(1,018)	(1,612)	(1,804)
Balance at end of period	7,567	9,255	7,567	9,255
Servicing liabilities:
Balance at beginning of period	1,420	2,022	1,517	2,217
Amortization	(182)	(185)	(279)	(380)
Balance at end of period	1,238	1,837	1,238	1,837
Serviced loans sold to unaffiliated parties	426,700		426,700		$ 448,600
Servicing fee income	1,100	1,200	2,200	2,400
Net amortization expense	$ 573	$ 833	$ 1,300	$ 1,400