Servicing Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Servicing assets:
Balance at beginning of period	$ 8,520	$ 10,218
Addition related to sale of SBA loans	315	435
Amortization	(857)	(786)
Balance at end of period	7,978	9,867
Servicing liabilities:
Balance at beginning of period	1,517	2,217
Amortization	(97)	(195)
Balance at end of period	1,420	2,022
Serviced loans sold to unaffiliated parties	438,400	448,600
Servicing fee income	1,100	1,100
Net amortization expense	$ 760	$ 591