Fair Value Measurements - Available-for-Sale Securities Measured at Fair Value (Parenthetical) (Detail) (Asset-backed securities and collateralized mortgage obligations [Member])	6 Months Ended
	Jun. 30, 2014
Asset-backed securities and collateralized mortgage obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Asset-backed and mortgage-backed securities with maturities	26 years