Leases - Adoption of ASC 842 (Details) - USD ($)	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
ASSETS
Right-of-use operating lease assets	$ 1,411,000	$ 1,592,000	$ 0
Liabilities
Other accrued liabilities	4,900,000	6,077,000	6,099,000
Operating lease liabilities - current	558,000	650,000	0
Operating lease liabilities - non-current	845,000	942,000	0
Equity
Accumulated deficit	$ (103,762,000)	(102,473,000)	$ (102,495,000)
Accounting Standards Update 2016-02
ASSETS
Right-of-use operating lease assets		1,592,000
Liabilities
Other accrued liabilities		(22,000)
Operating lease liabilities - current		650,000
Operating lease liabilities - non-current		942,000
Equity
Accumulated deficit		$ 22,000