Consolidated Statement of Changes in Shareholders Equity (USD $) In Thousands, unless otherwise specified	Total	Preferred stock [Member]	Common stock [Member]	Common stock issuable [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss), net [Member]	Treasury stock [Member]
Beginning Balance at Dec. 31, 2010	$ 8,357,695	$ 740,657	$ 60,198	$ 4,189	$ 2,398,615	$ 5,426,701	$ (205,220)	$ (67,445)
Total comprehensive income	724,426					711,739	12,687
Acquisition of Wilmington Trust Corporation-common stock issued	405,557		2,348		403,209
Partial redemption of Series A preferred stock	(370,000)	(370,000)
Conversion of Series B preferred stock into 433,144 shares of common stock		(26,500)	192		21,754			4,554
Issuance of Series D preferred stock	495,000	500,000			(5,000)
Preferred stock cash dividends	(34,125)					(34,125)
Amortization of preferred stock discount		18,560				(18,560)
Stock-based compensation plans:
Compensation expense, net	32,352		36		650			31,666
Exercises of stock options, net	23,444		29		(6,691)			30,106
Directors' stock plan	1,028		2		414			612
Deferred compensation plans, net, including dividend equivalents	40			(123)	(203)	(141)		507
Other	1,395				1,395
Common stock cash dividends-$2.10 per share	(261,686)					(261,686)
Ending Balance at Sep. 30, 2011	9,375,126	862,717	62,805	4,066	2,814,143	5,823,928	(192,533)
Beginning Balance at Dec. 31, 2011	9,271,209	864,585	62,842	4,072	2,828,986	5,867,165	(356,441)
Total comprehensive income	859,671					733,305	126,366
Preferred stock cash dividends	(40,088)					(40,088)
Amortization of preferred stock discount		5,831				(5,831)
Stock-based compensation plans:
Compensation expense, net	37,883		228		37,655
Exercises of stock options, net	72,484		545		71,939
Stock purchase plan	10,101		75		10,026
Directors' stock plan	1,121		7		1,114
Deferred compensation plans, net, including dividend equivalents	(160)		5	(621)	576	(120)
Other	952				952
Common stock cash dividends-$2.10 per share	(267,646)					(267,646)
Ending Balance at Sep. 30, 2012	$ 9,945,527	$ 870,416	$ 63,702	$ 3,451	$ 2,951,248	$ 6,286,785	$ (230,075)