Operating Leases - Cost and Supplemental Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Jan. 01, 2019
Leases [Abstract]
Operating lease cost	$ 669	$ 680	$ 1,985	$ 1,953
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	680	693	2,107	2,012
Right of use assets obtained in exchange for lease obligations	51	$ 28	105	$ 1,616
Operating leases:
Operating lease assets	7,329		7,329		$ 8,991	$ 9,600
Operating lease liabilities	$ 8,204		$ 8,204		$ 9,990	$ 10,600
Weighted-average remaining lease term	4 years 4 months 24 days		4 years 4 months 24 days		5 years
Weighted-average discount rate	2.80%		2.80%		2.81%