Assets by Segments (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total assets	$ 2,229,018	$ 2,391,599
Operating Segments
Segment Reporting Information [Line Items]
Total assets	2,048,198	2,058,144
Operating Segments | Corporate Finance & Restructuring
Segment Reporting Information [Line Items]
Total assets	671,605	668,631
Operating Segments | Forensic and Litigation Consulting
Segment Reporting Information [Line Items]
Total assets	437,398	430,759
Operating Segments | Economic Consulting
Segment Reporting Information [Line Items]
Total assets	498,765	493,694
Operating Segments | Technology
Segment Reporting Information [Line Items]
Total assets	200,987	214,866
Operating Segments | Strategic Communications
Segment Reporting Information [Line Items]
Total assets	239,443	250,194
Unallocated Corporate Assets
Segment Reporting Information [Line Items]
Total assets	$ 180,820	$ 333,455