Stock Compensation Plans (Details Textual) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2011
Stock Compensation Plans (Textuals) [Abstract]
Total compensation cost related to non-vested awards not yet recognized	$ 113
Weighted average period of compensation cost recognized (in years)	1.5

The weighted average period over which unrecognized compensation is expected to be recognized for share-based compensation plans, using a decimal to express in number of years.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph h

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition
Namespace Prefix:	us-gaap
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration