Supplemental Condensed Consolidating Guarantor and Non-Guarantor Financial Information Condensed Consolidating Balance Sheet Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets
Cash and cash equivalents	$ 149,760	$ 283,680	$ 205,833	$ 156,785
Accounts receivable, net	499,784	485,101
Other current assets	92,081	88,060
Total current assets	741,625	856,841
Property and equipment, net	74,760	82,163
Goodwill	1,198,298	1,211,689	1,218,733
Other intangible assets, net	63,935	77,034
Other assets	150,400	163,872
Total assets	2,229,018	2,391,599
Liabilities
Other current liabilities	347,077	367,092
Total current liabilities	347,077	367,092
Long-term debt, net	494,772	688,404
Other liabilities	239,566	233,357
Total liabilities	1,081,415	1,288,853
Stockholders' equity	1,147,603	1,102,746	1,042,259	1,068,232
Total liabilities and stockholders' equity	2,229,018	2,391,599
FTI Consulting, Inc.
Assets
Cash and cash equivalents	35,211	171,090	111,943	66,663
Accounts receivable, net	159,121	153,495
Other current assets	44,086	47,123
Total current assets	238,418	371,708
Property and equipment, net	33,699	33,864
Goodwill	558,978	559,318
Other intangible assets, net	25,863	29,807
Investments in subsidiaries	1,995,409	1,915,869
Other assets	40,359	50,810
Total assets	2,892,726	2,961,376
Liabilities
Intercompany payables	930,066	832,253
Other current liabilities	135,421	148,299
Total current liabilities	1,065,487	980,552
Long-term debt, net	494,772	688,404
Other liabilities	184,864	189,674
Total liabilities	1,745,123	1,858,630
Stockholders' equity	1,147,603	1,102,746
Total liabilities and stockholders' equity	2,892,726	2,961,376
Guarantor Subsidiaries
Assets
Cash and cash equivalents	165	159	494	610
Accounts receivable, net	169,488	162,032
Intercompany receivables	936,452	875,000
Other current assets	25,627	22,994
Total current assets	1,131,732	1,060,185
Property and equipment, net	13,409	17,050
Goodwill	416,053	416,053
Other intangible assets, net	15,571	18,432
Investments in subsidiaries	486,462	484,162
Other assets	72,981	78,388
Total assets	2,136,208	2,074,270
Liabilities
Intercompany payables	8,921	14,197
Other current liabilities	107,188	113,450
Total current liabilities	116,109	127,647
Other liabilities	12,562	14,955
Total liabilities	128,671	142,602
Stockholders' equity	2,007,537	1,931,668
Total liabilities and stockholders' equity	2,136,208	2,074,270
Non-Guarantor Subsidiaries
Assets
Cash and cash equivalents	114,384	112,431	$ 93,396	$ 89,512
Accounts receivable, net	171,175	169,574
Intercompany receivables	62,651	12,195
Other current assets	22,368	17,943
Total current assets	370,578	312,143
Property and equipment, net	27,652	31,249
Goodwill	223,267	236,318
Other intangible assets, net	43,542	53,357
Other assets	37,060	34,674
Total assets	702,099	667,741
Liabilities
Intercompany payables	60,116	40,745
Other current liabilities	104,468	105,343
Total current liabilities	164,584	146,088
Other liabilities	42,140	28,728
Total liabilities	206,724	174,816
Stockholders' equity	495,375	492,925
Total liabilities and stockholders' equity	702,099	667,741
Eliminations
Assets
Intercompany receivables	(999,103)	(887,195)
Total current assets	(999,103)	(887,195)
Other intangible assets, net	(21,041)	(24,562)
Investments in subsidiaries	(2,481,871)	(2,400,031)
Total assets	(3,502,015)	(3,311,788)
Liabilities
Intercompany payables	(999,103)	(887,195)
Total current liabilities	(999,103)	(887,195)
Total liabilities	(999,103)	(887,195)
Stockholders' equity	(2,502,912)	(2,424,593)
Total liabilities and stockholders' equity	$ (3,502,015)	$ (3,311,788)