Supplemental Condensed Consolidating Guarantor and Non-Guarantor Financial Information (Condensed Consolidating Statement Of Comprehensive Income (Loss)) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Revenues	$ 414,613		$ 396,243	$ 821,791	$ 791,471
Operating expenses
Direct cost of revenues	259,528		248,220	518,008	493,838
Selling, general and administrative expense	96,325		92,460	192,972	195,049
Special charges		400	26,782	427	26,782	29,600
Acquisition-related contingent consideration	(7,452)		(3,541)	(6,721)	(2,984)
Amortization of other intangible assets	5,953		5,490	11,517	11,007
Operating income	60,259		26,832	105,588	67,779
Other (expense) income	(13,458)		(15,558)	(25,236)	(27,480)
Income (loss) before income tax provision	46,801		11,274	80,352	40,299
Income tax (benefit) provision	23,315		3,527	33,186	14,121
Net income	23,486		7,747	47,166	26,178
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net	(11,714)		(10,960)	(27,223)	1,889
Other comprehensive income (loss), net of tax	(11,714)		(10,960)	(27,223)	1,889
Comprehensive income	11,772		(3,213)	19,943	28,067
FTI Consulting, Inc.
Revenues	144,390		151,442	295,350	305,023
Operating expenses
Direct cost of revenues	92,781		96,450	193,618	197,625
Selling, general and administrative expense	38,575		39,041	81,471	86,435
Special charges			16,731	323	16,731
Acquisition-related contingent consideration	92			179
Amortization of other intangible assets	1,095		1,297	2,322	2,600
Operating income	11,847		(2,077)	17,437	1,632
Other (expense) income	(16,773)		(17,469)	(31,713)	(30,456)
Income (loss) before income tax provision	(4,926)		(19,546)	(14,276)	(28,824)
Income tax (benefit) provision	(4,290)		(9,666)	(7,221)	(28,380)
Equity in net earnings of subsidiaries	24,122		17,627	54,221	26,622
Net income	23,486		7,747	47,166	26,178
Other comprehensive income (loss), net of tax:
Comprehensive income	23,486		7,747	47,166	26,178
Guarantor Subsidiaries
Revenues	254,394		241,033	501,055	482,749
Operating expenses
Direct cost of revenues	192,526		180,788	379,873	362,737
Selling, general and administrative expense	28,614		28,507	56,590	57,559
Special charges			4,287	104	4,287
Acquisition-related contingent consideration	195			195
Amortization of other intangible assets	2,501		2,473	4,948	4,950
Operating income	30,558		24,978	59,345	53,216
Other (expense) income	202		(195)	531	35,987
Income (loss) before income tax provision	30,760		24,783	59,876	89,203
Income tax (benefit) provision	24,090		12,910	34,062	40,724
Equity in net earnings of subsidiaries	15,679		5,741	24,114	13,383
Net income	22,349		17,614	49,928	61,862
Other comprehensive income (loss), net of tax:
Comprehensive income	22,349		17,614	49,928	61,862
Non-Guarantor Subsidiaries
Revenues	113,565		101,451	221,561	203,509
Operating expenses
Direct cost of revenues	70,725		66,080	138,698	128,999
Selling, general and administrative expense	30,367		27,497	56,905	55,342
Special charges			5,764		5,764
Acquisition-related contingent consideration	(7,739)		(3,541)	(7,095)	(2,984)
Amortization of other intangible assets	3,146		2,541	5,829	5,097
Operating income	17,066		3,110	27,224	11,291
Other (expense) income	3,113		2,106	5,946	1,874
Income (loss) before income tax provision	20,179		5,216	33,170	13,165
Income tax (benefit) provision	3,515		283	6,345	1,777
Net income	16,664		4,933	26,825	11,388
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net	(11,714)		(10,960)	(27,223)	1,889
Other comprehensive income (loss), net of tax	(11,714)		(10,960)	(27,223)	1,889
Comprehensive income	4,950		(6,027)	(398)	13,277
Eliminations
Revenues	(97,736)		(97,683)	(196,175)	(199,810)
Operating expenses
Direct cost of revenues	(96,504)		(95,098)	(194,181)	(195,523)
Selling, general and administrative expense	(1,231)		(2,585)	(1,994)	(4,287)
Amortization of other intangible assets	(789)		(821)	(1,582)	(1,640)
Operating income	788		821	1,582	1,640
Other (expense) income					(34,885)
Income (loss) before income tax provision	788		821	1,582	(33,245)
Equity in net earnings of subsidiaries	(39,801)		(23,368)	(78,335)	(40,005)
Net income	(39,013)		(22,547)	(76,753)	(73,250)
Other comprehensive income (loss), net of tax:
Comprehensive income	$ (39,013)		$ (22,547)	$ (76,753)	$ (73,250)