General, Administrative and Other - Components of General, Administrative and Other Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other Income and Expenses [Abstract]
Professional services	$ 13,148	$ 23,375
Occupancy and equipment	10,903	9,328
Information processing and communications	7,029	10,349
Recurring placement and related service fees	5,444	12,531
Business development	2,757	4,669
Insurance	1,960	4,004
Other expenses	4,687	3,413
Total expenses before FCPA settlements expense	45,928	67,669
FCPA settlements expense	0	200,000
Total General, Administrative and Other	$ 45,928	$ 267,669