Revenue from Contract with Customer (Narrative) (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 4,618,000	$ 3,824,000
Contract liabilities	0	0
Receivables from contracts with customers
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 4,100,000	$ 2,200,000