Purchased Loans - Changes in Restructured Loans (Details) - Purchased $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) loan	Dec. 31, 2017 USD ($) loan
Number of Loans
Beginning balance (loans) | loan	72	42
Additional loans with concessions (loans) | loan	5	36
Reclassified as performing (loans) | loan	4	9
Reclassified as nonperforming (loans) | loan	(13)	(10)
Paid in full (loans) | loan	(14)	(3)
Charge-offs (loans) | loan		(1)
Principal paydowns (loans) | loan	0	0
Lapse of concession period (loans) | loan		(1)
Ending balance (loans) | loan	54	72
Recorded Investment
Beginning balance | $	$ 8,965	$ 4,028
Additional loans with concessions | $	712	5,703
Reclassified from nonperforming | $	435	838
Reclassified as nonperforming | $	(1,229)	(786)
Paid In full | $	(744)	(323)
Charge-offs | $		(17)
Principal paydowns | $	(644)	(377)
Lapse of concession period | $		(101)
Ending balance | $	$ 7,495	$ 8,965