Acquisition (Details) - USD ($)					3 Months Ended		12 Months Ended
	Oct. 20, 2017	Jan. 09, 2017	Nov. 01, 2016	Oct. 05, 2015	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2016
Business Acquisition [Line Items]
Goodwill					$ 149,333,000	$ 111,116,000	$ 131,995,000			$ 109,448,000
Revenues					45,197,000	45,175,000
Net loss					4,569,000	$ (2,357,000)
TempAlert
Business Acquisition [Line Items]
Purchase price before working capital adjustments	$ 45,000,000
Total purchase price consideration	40,741,000
Cash paid at closing	40,741,000
Cash acquired	600,000
Goodwill	$ 17,341,000
Weighted average use life of acquired intangibles	6 years 6 months
Revenues					2,100,000
Net loss					1,100,000
Acquisition costs					1,400,000		400,000
SMART Temps
Business Acquisition [Line Items]
Cash paid at closing		$ 28,800,000
Cash acquired		500,000
Goodwill		18,800,000
FreshTemp
Business Acquisition [Line Items]
Cash paid at closing			$ 1,700,000
Earn-out payment maximum			2,300,000
Goodwill			2,700,000
Acquisition costs					60,000
Bluenica Corporation
Business Acquisition [Line Items]
Cash paid at closing				$ 2,900,000
Earn-out payment maximum				11,600,000
Goodwill				$ 11,000,000
Earn-out payment installment period				4 years
Purchased and Core Technology | TempAlert
Business Acquisition [Line Items]
Estimated useful life of finite lived intangibles	5 years
Customer Relationships | TempAlert
Business Acquisition [Line Items]
Estimated useful life of finite lived intangibles	7 years
Trademarks and Trade Names | TempAlert
Business Acquisition [Line Items]
Estimated useful life of finite lived intangibles	5 years
Earn-out payments | SMART Temps
Business Acquisition [Line Items]
Earn-out payment maximum		7,200,000
Additional earn-out payment | Bluenica Corporation
Business Acquisition [Line Items]
Earn-out payment maximum				$ 3,500,000
Fair Value, Measurements, Recurring | Contingent Consideration | Estimate of Fair Value Measurement
Business Acquisition [Line Items]
Contingent consideration fair value					5,981,000		$ 6,388,000
Fair Value, Measurements, Recurring | Contingent Consideration | Estimate of Fair Value Measurement | TempAlert
Business Acquisition [Line Items]
Contingent consideration fair value	$ 0				0
Fair Value, Measurements, Recurring | Contingent Consideration | Estimate of Fair Value Measurement | SMART Temps
Business Acquisition [Line Items]
Contingent consideration fair value		$ 10,000			0
Fair Value, Measurements, Recurring | Contingent Consideration | Estimate of Fair Value Measurement | FreshTemp
Business Acquisition [Line Items]
Contingent consideration fair value			$ 1,300,000		300,000
Fair Value, Measurements, Recurring | Contingent Consideration | Estimate of Fair Value Measurement | Bluenica Corporation
Business Acquisition [Line Items]
Contingent consideration fair value				$ 10,400,000	$ 5,600,000
Forecast | Earn-out payments | TempAlert
Business Acquisition [Line Items]
Earn-out payment maximum								$ 45,000,000	$ 35,000,000