Leases (Schedule of Lease Costs and Other Lease Information) (Details)	3 Months Ended
	Mar. 31, 2019 USD ($)
Operating lease
Operating lease cost	$ 148,000
Short-term lease cost	130,000
Variable lease cost	17,000
Sublease income
Total lease cost	295,000
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	147,000
Lease right-of-use assets obtained in exchange for new lease liabilities
Lease right-of-use assets obtained in exchange for new lease liabilities - operating leases	$ 1,680,000