ACQUISITIONS - Advantage RN (Details) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	Jul. 28, 2017	Jul. 01, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Cash consideration					$ 85,977	$ 0
Borrowings on debt					62,000	40,000
Acquisition related costs			$ 1,366	$ 0	1,953	$ 0
Advantage RN, LLC [Member]
Business Acquisition [Line Items]
Cash consideration		$ 86,562
Net working capital adjustment		600
Reimbursement from working capital adjustment settled			800
Contingent liability			300		$ 300
Release of remaining contingent liability			300
Escrow payment related to tax liabilities		14,500
Escrow payment related to post-close liabilities		7,500
Release of escrow to seller	$ 7,300
Escrow deposit related to tax liabilities	$ 7,200
Consideration transferred, available cash		19,900
Revenue since acquisition			24,500
Net income since acquisition			2,100
Assets acquired		$ 29,900
Weighted average useful life of assets acquired		10 years
Goodwill expected to be deductible		$ 43,600
Acquisition related costs			$ 1,400
Trade names [Member] | Advantage RN, LLC [Member]
Business Acquisition [Line Items]
Assets acquired		$ 4,500
Weighted average useful life of assets acquired		10 years
Customer relationships [Member] | Advantage RN, LLC [Member]
Business Acquisition [Line Items]
Assets acquired		$ 13,800
Weighted average useful life of assets acquired		10 years
Databases [Member] | Advantage RN, LLC [Member]
Business Acquisition [Line Items]
Assets acquired		$ 11,300
Weighted average useful life of assets acquired		10 years
Non-compete agreements [Member] | Advantage RN, LLC [Member]
Business Acquisition [Line Items]
Assets acquired		$ 300
Weighted average useful life of assets acquired		5 years
Deferred Consideration Transferred [Member] | Advantage RN, LLC [Member]
Business Acquisition [Line Items]
Contingent liability		$ 600
Period of deferred consideration		20 months
Credit Agreement [Member]
Business Acquisition [Line Items]
Borrowings on debt		$ 66,900
Term Loan [Member] | Incremental Term Loan [Member]
Business Acquisition [Line Items]
Borrowings on debt		40,000
Physician Staffing [Member] | Advantage RN, LLC [Member]
Business Acquisition [Line Items]
Percentage of results aggregated into segment, less than			2.00%		2.00%
Purchase Price [Member] | Advantage RN, LLC [Member]
Business Acquisition [Line Items]
Purchase price		$ 88,000