Goodwill and Other Intangible Assets - Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Intangible asset amortization expense, excluding impairment charge	$ 1,400	$ 1,200
Estimated intangible asset amortization expense 2015	4,931
Estimated intangible asset amortization expense 2016	4,983
Estimated intangible asset amortization expense 2017	3,707
Estimated intangible asset amortization expense 2018	2,712
Estimated intangible asset amortization expense 2019	1,305
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	2,760
Finite-Lived Intangible Assets, Net	20,398		$ 18,687
Executive Search and Leadership Consulting [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net	6,287		3,521
Americas [Member] | Executive Search and Leadership Consulting [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	3,200
Goodwill, Acquired During Period	5,447
Finite-Lived Intangible Assets, Net	$ 3,897		$ 764