Fair Value Measurements - General information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Loans Held for Sale
Other information
Period of originated loans within which they are transferred or sold	60 days
Maximum
Other information
Term Of Maturity Of Investments	90 days
Investment period for loans held for investment	3 years
Level 3
Other information
Credit Adjustments to Loans Held for investment	$ 0.0	$ 0.0