Leases - Summary (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) item	Mar. 31, 2018 USD ($)
Leases
Number of options to extend | item	1
Extension term	5 years
Option to extend lease term	true
Operating lease, Right-of-use asset	$ 1,100
Operating lease, ROU asset, Statement of Financial Position	us-gaap:PropertyPlantAndEquipmentNet
Operating lease, liability	$ 1,124
Operating lease, liability, Statement of Financial Position	us-gaap:AccruedLiabilitiesAndOtherLiabilities
Lease expense	$ 123	$ 121
Cash paid for amounts included in the measurement of lease liabilities for operating leases:	134
ROU assets obtained in exchange for lease liabilities	$ 1,120
Weighted average remaining lease term in months	25 years
Weighted average discount rate	2.75%