Employee Benefit Plans - Additional Information (Detail) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Foreign Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan arrangement minimum age				60 years
Defined benefit plan arrangement requisite service period				5 years
Defined benefit plan assumptions used calculating benefit obligation benefits payable per service year				One-half month's salary for each year of credited service
Description of defined benefit pension and other post retirement plans				The plan defines retirement as those employees who have attained the age of 60 and have completed at least five years of credited service. Benefits payable under the plan equate to one-half month’s salary for each year of credited service. Benefits under the plan are paid out as a lump sum to eligible employees at retirement.
Net periodic benefit cost	$ 68,000		$ 53,000	$ 199,000	$ 164,000
Defined benefit plan, benefit obligation	1,600,000			1,600,000		1,400,000
Contributions made to the SERP				0
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan arrangement minimum age				55 years
Defined benefit plan arrangement requisite service period				10 years
Description of defined benefit pension and other post retirement plans				Normal retirement age under the SERP is defined as age 65; however, certain conditions allow for early retirement as early as age 55 or upon a change in control. Vesting under the plan is defined as 100% upon a participant’s attainment of age 55 and 10 years of service and 0% prior to a participant’s attainment of age 55 and 10 years of service. Full vesting also occurs if a participant with five years or more of service is involuntarily terminated by Kforce without cause or upon death, disability or a change in control. The SERP is funded entirely by Kforce, and benefits are taxable to the covered executive officer upon receipt and deductible by Kforce when paid. Benefits payable under the SERP upon the occurrence of a qualifying distribution event, as defined, are targeted at 45% of the covered executive officers’ average salary and bonus, as defined, from the three years in which the covered executive officer earned the highest salary and bonus during the last 10 years of employment, which is subject to adjustment for retirement prior to the normal retirement age and the participant’s vesting percentage. The benefits under the SERP are reduced for a participant that has not reached age 62 with 10 years of service or age 55 with 25 years of service with a percentage reduction up to the normal retirement age. Benefits under the SERP are normally paid based on the lump sum present value but may be paid over the life of the covered executive officer or as a 10-year annuity, as elected by the covered executive officer upon commencement of participation in the SERP. None of the benefits earned pursuant to the SERP are attributable to services provided prior to the effective date of the plan. For purposes of the measurement of the benefit obligation, Kforce has assumed that all participants will elect to take the lump sum present value option based on historical trends.
Net periodic benefit cost	365,000		691,000	1,094,000	2,073,000
Defined benefit plan, benefit obligation	8,900,000			8,900,000		7,900,000
Contributions made to the SERP				0
Benefits payable targeted percentage				45.00%
Lump sum payment period				10 years
Defined benefit plan assumptions used calculating benefit obligation benefits payable calculation				Benefits payable under the SERP upon the occurrence of a qualifying distribution event, as defined, are targeted at 45% of the covered executive officers’ average salary and bonus, as defined, from the three years in which the covered executive officer earned the highest salary and bonus during the last 10 years of employment, which is subject to adjustment for retirement prior to the normal retirement age and the participant’s vesting percentage. The benefits under the SERP are reduced for a participant that has not reached age 62 with 10 years of service or age 55 with 25 years of service with a percentage reduction up to the normal retirement age.
Defined benefit plan assumptions used calculating benefit obligation benefits payment election				Benefits under the SERP are normally paid based on the lump sum present value but may be paid over the life of the covered executive officer or as a 10-year annuity, as elected by the covered executive officer upon commencement of participation in the SERP. None of the benefits earned pursuant to the SERP are attributable to services provided prior to the effective date of the plan. For purposes of the measurement of the benefit obligation, Kforce has assumed that all participants will elect to take the lump sum present value option based on historical trends."
Postretirement Health Coverage [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost	931,000		232,000	977,000	695,000
Settlement loss/gain	(847,000)	122,000	0	(725,000)	0
Lump-sum payment to the participant	3,200,000	639,000
Defined benefit plan accumulated benefit obligation non-current	0			0		2,600,000
Defined benefit plan accumulated benefit obligation current	$ 0			$ 0		$ 47,000