Acquired Loans - Components of the Allowance for Loan Losses on Acquired Loans (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period		$ 4,079	$ 11,397	$ 11,992
Transfers	[1]	(1,554)
Provision for loan losses, acquired loans		(1,005)	(7,395)	3,757
Net (charge-offs) recoveries		(289)	77	(4,352)
Balance at end of period		$ 1,231	$ 4,079	$ 11,397

[1] The allowance for loan losses balance related to the remaining loans acquired in the Heritage acquisition, the Bay Bank merger and the Reliance merger, which were transferred from acquired impaired loans to LHFI during 2018