Business Combinations - Stone Temple (Details) - USD ($) $ in Thousands		3 Months Ended
	Jul. 16, 2018	Mar. 31, 2019	Mar. 31, 2018
Business Acquisition [Line Items]
Adjustment to fair value of contingent consideration for purchase of business		$ (424)	$ 969
Stone Temple Consulting Corporation
Business Acquisition [Line Items]
Date of acquisition	Jul. 16, 2018
Total purchase price	$ 12,300
Cash paid for acquisition	9,900
Common stock issued	1,100
Net working capital settlement	100
Initial fair value estimate of additional earnings-based contingent consideration	$ 1,200
Contingent consideration, maximum cash payout		2,600
Tax deductible amount of Goodwill		5,400
Fair value of contingent consideration		0
Adjustment to fair value of contingent consideration for purchase of business		$ (1,300)