Income Tax Provision (Deferred Tax Assets and Liabilities) (Details) (USD $)	3 Months Ended
	Sep. 30, 2013	Mar. 31, 2013
Deferred Tax Assets Liabilities, Net [Line Items]
Net deferred income tax liability	$ 6,461,000,000	$ 6,236,000,000
Tax Assets
Deferred tax assets	1,200,000,000	1,200,000,000
Net deferred income tax liability	6,461,000,000	6,236,000,000
Valuation allowance, deferred tax asset, change in amount, capital loss carryforward	$ 1,000,000