Supplemental Condensed Consolidating Guarantor and Non-Guarantor Financial Information (Condensed Consolidating Statement Of Comprehensive Income) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Revenues	$ 407,178	$ 395,228
Operating expenses
Direct cost of revenues	258,480	245,618
Selling, general and administrative expense	96,647	102,589
Special charges	427		29,600
Acquisition-related contingent consideration	731	557
Amortization of other intangible assets	5,564	5,517
Operating income	45,329	40,947
Other (expense) income	(11,778)	(11,922)
Income (loss) before income tax provision	33,551	29,025
Income tax (benefit) provision	9,871	10,594
Net income	23,680	18,431
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax $0	(15,509)	12,849
Other comprehensive income (loss), net of tax	(15,509)	12,849
Comprehensive income	8,171	31,280
FTI Consulting, Inc.
Revenues	150,960	153,581
Operating expenses
Direct cost of revenues	100,837	101,175
Selling, general and administrative expense	42,896	47,394
Special charges	323
Acquisition-related contingent consideration	87
Amortization of other intangible assets	1,227	1,303
Operating income	5,590	3,709
Other (expense) income	(14,940)	(12,987)
Income (loss) before income tax provision	(9,350)	(9,278)
Income tax (benefit) provision	(2,931)	(18,714)
Equity in net earnings of subsidiaries	30,099	8,995
Net income	23,680	18,431
Other comprehensive income (loss), net of tax:
Comprehensive income	23,680	18,431
Guarantor Subsidiaries
Revenues	246,661	241,716
Operating expenses
Direct cost of revenues	187,347	181,949
Selling, general and administrative expense	27,976	29,052
Special charges	104
Amortization of other intangible assets	2,447	2,477
Operating income	28,787	28,238
Other (expense) income	329	36,182
Income (loss) before income tax provision	29,116	64,420
Income tax (benefit) provision	9,972	27,814
Equity in net earnings of subsidiaries	8,435	7,642
Net income	27,579	44,248
Other comprehensive income (loss), net of tax:
Comprehensive income	27,579	44,248
Non-Guarantor Subsidiaries
Revenues	107,996	102,058
Operating expenses
Direct cost of revenues	67,973	62,919
Selling, general and administrative expense	26,538	27,845
Acquisition-related contingent consideration	644	557
Amortization of other intangible assets	2,683	2,556
Operating income	10,158	8,181
Other (expense) income	2,833	(232)
Income (loss) before income tax provision	12,991	7,949
Income tax (benefit) provision	2,830	1,494
Net income	10,161	6,455
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax $0	(15,509)	12,849
Other comprehensive income (loss), net of tax	(15,509)	12,849
Comprehensive income	(5,348)	19,304
Eliminations
Revenues	(98,439)	(102,127)
Operating expenses
Direct cost of revenues	(97,677)	(100,425)
Selling, general and administrative expense	(763)	(1,702)
Amortization of other intangible assets	(793)	(819)
Operating income	794	819
Other (expense) income		(34,885)
Income (loss) before income tax provision	794	(34,066)
Equity in net earnings of subsidiaries	(38,534)	(16,637)
Net income	(37,740)	(50,703)
Other comprehensive income (loss), net of tax:
Comprehensive income	$ (37,740)	$ (50,703)