Discontinued Operations - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended			0 Months Ended	3 Months Ended	0 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 03, 2014	Mar. 31, 2012	Mar. 31, 2012
Schedule of Discontinued Operations [Line Items]
Gain on sale of discontinued operations before income tax	$ 94,300,000
Gain on sale of discontinued operations after income tax	56,100,000
Transaction costs	11,000,000
Stock based compensation related to acceleration of restricted stock and transaction bonuses paid in stock	2,400,000
Recognized compensation expense		1,100,000
Payroll taxes			1,200,000	1,000,000	10,200,000
Income tax expense as a percentage of income from discontinued operations			40.60%	40.10%	43.70%
Kforce Healthcare, Inc [Member] | RCM Acquisition Inc [Member]
Schedule of Discontinued Operations [Line Items]
Purchase Price For Divestiture Of Business						119,000,000
Post closing working capital adjustment						96,000
Health Information Management [Member]
Schedule of Discontinued Operations [Line Items]
Gain on sale of discontinued operations before income tax			94,300,000
Gain on sale of discontinued operations after income tax			56,100,000
Transaction costs			11,000,000
Stock based compensation related to acceleration of restricted stock and transaction bonuses paid in stock			2,400,000
Recognized compensation expense			600,000
Kforce Clinical Research, Inc [Member]
Schedule of Discontinued Operations [Line Items]
Recognized compensation expense		22,200,000					31,300,000
Payroll taxes							800,000
Stock Purchase Agreement [Member] | inVentiv Health, Inc. [Member] | Private Placement [Member]
Schedule of Discontinued Operations [Line Items]
Indemnification Deductible					375,000
Indemnification Aggregate Cap					5,000,000
Indemnification obligations period			18 months					18 months
Kforce Clinical Research, Inc.[Member] | Stock Purchase Agreement [Member] | RCM Acquisition Inc [Member] | Private Placement [Member]
Schedule of Discontinued Operations [Line Items]
Stock purchase agreement date			Aug. 04, 2014
Effective date of stock acquisition			Aug. 03, 2014
Kforce Clinical Research, Inc.[Member] | Stock Purchase Agreement [Member] | inVentiv Health, Inc. [Member] | Private Placement [Member]
Schedule of Discontinued Operations [Line Items]
Purchase Price For Divestiture Of Business								57,300,000
Post closing working capital adjustment								7,300,000
Stock purchase agreement date			Mar. 17, 2012
Effective date of stock acquisition			Mar. 31, 2012
Kforce Clinical Research, Inc.[Member] | Transition Services Agreement [Member] | inVentiv Health, Inc. [Member] | Private Placement [Member] | Maximum [Member]
Schedule of Discontinued Operations [Line Items]
Post-closing transitional services period								18 months
Transition Services Agreement [Member] | Kforce Healthcare, Inc [Member] | RCM Acquisition Inc [Member]
Schedule of Discontinued Operations [Line Items]
Post-closing transitional services period						12 months
Indemnification Agreement [Member] | Stock Purchase Agreement [Member] | RCM Acquisition Inc [Member]
Schedule of Discontinued Operations [Line Items]
Indemnification Deductible			1,190,000
Indemnification Aggregate Cap			$ 8,925,000