Sale of Trust Accounts - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended
	Apr. 30, 2015	Jun. 30, 2015	Mar. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Gain on sale of business net of tax	$ 23,000,000
Gain on sale of business before tax	45,000,000
Goodwill recorded	$ 11,000,000
Revenue on sale of business		$ 0	$ 9,000,000