Merger Agreement (Details Textual) (USD $)	Jan. 29, 2012 Lawsuits
Merger Agreement (Textual) [Abstract]
Cash to be received on the conversion of each common share	$ 72.00
Approximate total purchase consideration	$ 3,900,000,000
Termination fee payable upon termination of merger agreement	$ 116,000,000
Number of punitive class action lawsuits challenging the merger	5