Other Borrowings - Summary of Balances of Other Borrowings (Parenthetical) (Detail) (Other collateralized borrowings, fixed rate, as of December 31, 2014 of 0.05%, payable on January 2, 2014 [Member])	3 Months Ended
	Mar. 31, 2015
Other collateralized borrowings, fixed rate, as of December 31, 2014 of 0.05%, payable on January 2, 2014 [Member]
Debt Instrument [Line Items]
Other collateralized borrowings, fixed rate	0.05%
Other collateralized borrowings, maturity date	Apr. 01, 2015