Leases (Details)	9 Months Ended
	Sep. 30, 2019 USD ($) ft²	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Leases
Area of leased property (in square feet) | ft²	19,467
Operating lease, option to extend	true
Operating lease, extension term	3 years
Variable lease payments	$ 0
Residual value guarantee	0
Operating lease right-of-use assets	2,981,000
Operating lease liability	$ 3,036,000
ASU 2016-02
Leases
Operating lease right-of-use assets			$ 1,086,000
Adjustment [Member] | ASU 2016-02
Leases
Operating lease right-of-use assets		$ 1,086,000
Operating lease liability		$ 1,100,000