Assets by Segments (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total assets	$ 2,225,368	$ 2,229,018
Operating Segments
Segment Reporting Information [Line Items]
Total assets	1,982,587	2,048,198
Operating Segments | Corporate Finance & Restructuring
Segment Reporting Information [Line Items]
Total assets	681,919	671,605
Operating Segments | Forensic and Litigation Consulting
Segment Reporting Information [Line Items]
Total assets	400,047	437,398
Operating Segments | Economic Consulting
Segment Reporting Information [Line Items]
Total assets	496,757	498,765
Operating Segments | Technology
Segment Reporting Information [Line Items]
Total assets	189,704	200,987
Operating Segments | Strategic Communications
Segment Reporting Information [Line Items]
Total assets	214,160	239,443
Unallocated Corporate Assets
Segment Reporting Information [Line Items]
Total assets	$ 242,781	$ 180,820