Restructuring Expense (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2019
Activity in accrued restructuring expense
Impairment of right-of-use assets		$ 1,328,000
Termination of certain employees and exit of an office facility
Activity in accrued restructuring expense
Accrued restructuring, beginning of the period	$ 1,047,000
Provision for restructuring charges		1,561,000
Cash payments	(441,000)	(955,000)
Accrued restructuring, end of the period	$ 606,000	606,000
Expected restructuring costs			$ 606,000
Impairment of right-of-use assets		1,300,000
Write-off of fixed assets		$ 170,000