Other Assets and Other Liabilities - Schedule of Other Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Accrued expenses	$ 155,551	$ 124,721
Current income taxes and other taxes	123,548	99,278
Employee benefit-related liabilities	69,201	84,703
Deferred lease incentives	85,028	84,287
Unclaimed funds at LFB	14,962	24,997
Deferred revenue	45,390	35,717
Contingent consideration liability	28,941	22,608
Securities sold, not yet purchased	7,338	4,482
Other	43,629	56,653
Total	$ 573,588	$ 537,446