Leases (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
Operating lease liabilities	$ 20,175,000		$ 20,175,000		$ 20,203,000
Operating lease right-of-use assets	$ 18,598,000		$ 18,598,000		18,651,000
Operating lease, weighted average remaining lease term	10 years 11 months 15 days		10 years 11 months 15 days
Lessee, operating lease, discount rate	3.50%		3.50%
Operating lease, lease not yet commenced	$ 0		$ 0
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating lease liabilities					20,200,000
Operating lease right-of-use assets					$ 18,700,000
Rent expense		$ 737,000		$ 1,500,000
Related Parties Lease Transaction
Lessee, Lease, Description [Line Items]
Sale leaseback transaction	$ 0		$ 0