Acquisitions (Details 3) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Summary of merger-related expenses
Salaries and employee benefits	$ 325,197	$ 246,389	$ 891,465	$ 756,296
Equipment and net occupancy	68,101	54,353	184,434	165,185
Printing, postage and supplies	10,593	7,820	29,518	25,412
Other costs of operations	214,026	140,006	516,209	392,841
Total merger-related expenses		0	67,000	0
K Bank and Wilmington Trust Corporation Acquisition [Member]
Summary of merger-related expenses
Salaries and employee benefits	285		15,597
Equipment and net occupancy	119		223
Printing, postage and supplies	723		1,188
Other costs of operations	24,876		50,286
Total merger-related expenses	$ 26,003		$ 67,294