Leases - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Lessee Lease Description [Line Items]
Description of operating lease expiration terms			operating leases and their terms expire between 2019 and 2030 and, in some instances, contain options to renew for periods up to 30 years.
Renewal option period for operating leases	30 years		30 years
Existence of option to expire			true
Right-of-use asset	$ 35,604,000		$ 35,604,000
Total rental expense	1,400,000	$ 1,100,000	2,700,000	$ 2,200,000
Operating leases, minimum annual rental payments, receivable under sublease			$ 32,000
Operating leases minimum annual rental payments receivable under sublease agreement expired date			Jul. 31, 2019
Operating leases, rental income under sublease	16,000	$ 16,000	$ 32,000	$ 32,000
Optima Bank And Trust Company
Lessee Lease Description [Line Items]
Right-of-use asset	$ 4,700,000		$ 4,700,000