Investments of Insurance Subsidiaries - Schedule of Maturities of Investments (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014
Amortized Cost And Fair Value Debt Securities [Abstract]
Due in one year or less, Amortized Cost	$ 41
Due after one year through five years, Amortized Cost	232
Due after five years through ten years, Amortized Cost	90
Due after ten years, Amortized Cost	113
Amortized Cost, Total	476
Due in one year or less, Fair Value	41
Due after one year through five years, Fair Value	238
Due after five years through ten years, Fair Value	96
Due after ten years, Fair Value	117
Fair Value, Total	$ 492