Acquisition (Summary Of Impact Of Acquisition In The Financial Results) (Details) (USD $) In Millions, unless otherwise specified	5 Months Ended		12 Months Ended
	Dec. 31, 2011 Sterling [Member]		Dec. 31, 2011 Pro Forma Combined [Member]		Dec. 31, 2010 Pro Forma Combined [Member]
Total revenue	$ 132	[1]
Net income	55
Total revenue			2,544	[1]	2,731	[1]
Net income			$ 364		$ 346

[1] Net interest income and noninterest income