Restructuring Activities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring charge	$ 119,000	$ 1,428,000	$ 219,000
Restructuring liability, beginning balance	309,000	0
Amounts expensed	125,000	1,428,000
Amounts expensed - discontinued operations	581,000
Amounts paid	(624,000)	(1,119,000)
Restructuring liability, ending balance	391,000	$ 309,000	$ 0
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charge	$ 706,000