Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) reporting_unit segment shares	Dec. 31, 2016 USD ($) shares
Property, Plant and Equipment [Line Items]
Number of segments | segment	2
Change in fair value of contingent consideration liability	$ (1,000,000)
Deferred compensation liability	3,900,000	$ 3,800,000
Contingent consideration liability	3,000,000	4,000,000
Net rental loss on rental contracts	(683,000)	(662,000)
Amortization of capitalized software costs	2,700,000	1,100,000
Insurance recovery (loss) on investment	0	771,000
Capitalized software costs	3,800,000	2,700,000
Impairment of intangible assets	$ 0	500,000
Number of operating segments | segment	2
Number of reportable units | reporting_unit	2
Amount outstanding for goodwill within continuing operations	$ 11,051,000	11,051,000
Impairment of goodwill	0	0
Intangible assets impairment charge		500,000
Adoption of accounting standard on deferred taxes	$ 578,000	$ (578,000)
Employee Stock Option
Property, Plant and Equipment [Line Items]
Incremental shares excluded from computation of diluted earnings per share (in shares) | shares	265,000	38,000
Restricted Stock
Property, Plant and Equipment [Line Items]
Incremental shares excluded from computation of diluted earnings per share (in shares) | shares	0	0
Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	25 years
Brink Software
Property, Plant and Equipment [Line Items]
Change in fair value of contingent consideration liability	$ (1,000,000)	$ (1,100,000)
Retained Earnings
Property, Plant and Equipment [Line Items]
Adoption of accounting standard on deferred taxes		(578,000)
Retained Earnings | Accounting Standards Update 2016-09
Property, Plant and Equipment [Line Items]
Adoption of accounting standard on deferred taxes		$ 578,000
Income approach valuation technique
Property, Plant and Equipment [Line Items]
Weighting of valuation method	80.00%
Long-term growth rate	3.00%
Income approach valuation technique | Minimum
Property, Plant and Equipment [Line Items]
Discount rate	14.50%
Income approach valuation technique | Maximum
Property, Plant and Equipment [Line Items]
Discount rate	27.00%
Market approach valuation technique, public company method
Property, Plant and Equipment [Line Items]
Weighting of valuation method	10.00%
Market approach valuation technique, quoted market price method
Property, Plant and Equipment [Line Items]
Weighting of valuation method	10.00%
Software and Software Development Costs | Minimum
Property, Plant and Equipment [Line Items]
Useful life of intangibles	3 years
Software and Software Development Costs | Maximum
Property, Plant and Equipment [Line Items]
Useful life of intangibles	7 years