Commitments and Contingencies (Details) $ in Thousands	May 10, 2017 USD ($)	Mar. 31, 2018 USD ($) operating_lease states	Jan. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2015 operating_lease
Loss Contingencies [Line Items]
Number of operating leases settlements | states		3
Accrued lease settlement liability		$ 200
Other current liabilities		4,762	$ 5,487	$ 5,529
Provant
Loss Contingencies [Line Items]
Litigation settlement amount	$ 800
Provant
Loss Contingencies [Line Items]
Accrued purchased commitment obligation related to vendor		1,300
Other Current Liabilities | Employment-related claim
Loss Contingencies [Line Items]
Loss contingency accrual		200
Other Current Liabilities | Provant
Loss Contingencies [Line Items]
Other current liabilities		700
Employee Severance | Other Current Liabilities
Loss Contingencies [Line Items]
Restructuring reserve		$ 400		$ 600
Olathe, KS and East Greenwich, RI
Loss Contingencies [Line Items]
Number of properties under operating leases | operating_lease		2
Des Moines, IA and Indianapolis
Loss Contingencies [Line Items]
Number of properties under operating leases | operating_lease					2