Commitments, Contingencies and Guarantees - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($) attorney_general_office
Loss Contingencies [Line Items]
Contractual obligation	$ 400.0
Other liabilities reserve	$ 0.2
Loss contingency, loss emergence period	1 year
Number of attorneys general | attorney_general_office	2