v2.4.0.8
Investments - Held To Maturity - Additional Information (Detail) (USD $)
Jun. 30, 2014
Schedule of Held-to-maturity Securities [Line Items]  
Commitment amount upon closing merger transaction $ 2,000,000,000
Held to maturity investments, amortized cost 1,500,000,000
Held to maturity investments, recorded basis 1,500,000,000
Held to maturity investments, estimated fair value 1,700,000,000
Held to maturity investments, gross unrecognized holding gains 164,000,000
Held to maturity investments, unrealized loss position $ 0