ACQUISITIONS (Narrative) (Details) $ in Thousands							3 Months Ended		12 Months Ended
	Nov. 16, 2015 USD ($)	Jul. 10, 2015 USD ($)	Oct. 31, 2014 USD ($) shares	Jun. 06, 2014 USD ($) shares	Apr. 30, 2014 USD ($) shares	Mar. 05, 2014 USD ($) shares	Jun. 30, 2015 shares	Mar. 31, 2015 shares	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) shares
Minimum
Business Acquisition [Line Items]
Estimated future operating results period, subsequent to acquisition date										7 months
Maximum
Business Acquisition [Line Items]
Estimated future operating results period, subsequent to acquisition date										12 months
2015 Acquisitions | NavigationArts
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment | $									$ 1,797
Cash consideration placed in escrow | $		$ 2,670
Consideration placed in escrow, period		18 months
2015 Acquisitions | NavigationArts | Design Consultant
Business Acquisition [Line Items]
Numbers of professionals acquired		90
2015 Acquisitions | AGS
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment | $									$ (140)
Cash consideration placed in escrow | $	$ 5,000
Consideration placed in escrow, period	15 months
2015 Acquisitions | AGS | IT professionals
Business Acquisition [Line Items]
Numbers of professionals acquired	1,151
2014 Acquisition | Netsoft
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment | $										$ (348)
2014 Acquisition | Netsoft | IT professionals
Business Acquisition [Line Items]
Numbers of professionals acquired						40
2014 Acquisition | Jointech
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment | $										0
Number of former owners					2
2014 Acquisition | Jointech | IT professionals
Business Acquisition [Line Items]
Numbers of professionals acquired					216
2014 Acquisition | GGA
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment | $										1,366
2014 Acquisition | GGA | IT professionals
Business Acquisition [Line Items]
Numbers of professionals acquired				329
2014 Acquisition | GGA | Scientists
Business Acquisition [Line Items]
Numbers of professionals acquired				126
2014 Acquisition | Great Fridays
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment | $										$ (77)
2014 Acquisition | Great Fridays | Designers
Business Acquisition [Line Items]
Numbers of professionals acquired			50
2014 Acquisition | Employment Shares | Netsoft
Business Acquisition [Line Items]
Vesting period (in years)						3 years			3 years
Stock issued or issuable, value assigned | $						$ 1,017
2014 Acquisition | Employment Shares | Jointech
Business Acquisition [Line Items]
Vesting period (in years)					3 years				3 years
Stock issued or issuable, value assigned | $					$ 7,788
2014 Acquisition | Employment Shares | GGA
Business Acquisition [Line Items]
Vesting period (in years)				3 years					3 years
Stock issued or issuable, value assigned | $				$ 20,655
2014 Acquisition | Employment Shares | Great Fridays
Business Acquisition [Line Items]
Vesting period (in years)			3 years						3 years
Stock issued or issuable, value assigned | $			$ 4,823
2014 Acquisition | Employment Shares, Closing Shares | Netsoft
Business Acquisition [Line Items]
Common Shares, Issued (in shares)						2,289
2014 Acquisition | Employment Shares, Closing Shares | Jointech
Business Acquisition [Line Items]
Common Shares, Issued (in shares)					89,552
2014 Acquisition | Employment Shares, Closing Shares | GGA
Business Acquisition [Line Items]
Common Shares, Issued (in shares)				262,277
2014 Acquisition | Employment Shares, Closing Shares | Great Fridays
Business Acquisition [Line Items]
Common Shares, Issued (in shares)			90,864
2014 Acquisition | Employment Shares, Earn-Out Shares | Netsoft
Business Acquisition [Line Items]
Common Shares, Issued (in shares)								16,349
Common Shares, Deferred (in shares)						9,154
2014 Acquisition | Employment Shares, Earn-Out Shares | Jointech
Business Acquisition [Line Items]
Common Shares, Issued (in shares)							83,057
2014 Acquisition | Employment Shares, Earn-Out Shares | GGA
Business Acquisition [Line Items]
Common Shares, Issued (in shares)							233,753
2014 Acquisition | Employment Shares, Earn-Out Shares | Great Fridays
Business Acquisition [Line Items]
Common Shares, Issued (in shares)							10,092
2014 Acquisition | Common Stock
Business Acquisition [Line Items]
Common Shares, Issued (in shares)											0
Common Shares, Deferred (in shares)											89,552
Stock issued or issuable, value assigned | $											$ 0
2014 Acquisition | Common Stock | Netsoft
Business Acquisition [Line Items]
Common Shares, Issued (in shares)						0
Common Shares, Deferred (in shares)						0
Stock issued or issuable, value assigned | $						$ 0
2014 Acquisition | Common Stock | Jointech
Business Acquisition [Line Items]
Common Shares, Issued (in shares)					0
Common Shares, Deferred (in shares)					89,552
Stock issued or issuable, value assigned | $					$ 0
2014 Acquisition | Common Stock | GGA
Business Acquisition [Line Items]
Common Shares, Issued (in shares)				0
Common Shares, Deferred (in shares)				0
Stock issued or issuable, value assigned | $				$ 0
2014 Acquisition | Common Stock | Great Fridays
Business Acquisition [Line Items]
Common Shares, Issued (in shares)			0
Common Shares, Deferred (in shares)			0
Stock issued or issuable, value assigned | $			$ 0