Redeemable Noncontrolling Interest (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	1 Months Ended
	Nov. 30, 2011	Mar. 31, 2011 Common Stock [Member] Subsidiaries [Member]	Nov. 30, 2011 Fair Value, Inputs, Level 3 [Member]
Redeemable Noncontrolling Interest [Line Items]
Business Acquisition Equity Interests Issued Or Issuable Percent Of Shares Issued		20.00%
Period In Which Noncontrolling Interest Becomes Redeemable	60 days
Redeemable Noncontrolling Interest, Equity, Fair Value			$ 19