Segment Reporting (Details 3) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
"Core Earnings" adjustments to GAAP:
Net interest income after provisions for loan losses	$ 577,721,000	$ 513,683,000	$ 1,172,282,000	$ 1,009,040,000
Total other income (loss)	(328,060,000)	367,314,000	(333,661,000)	600,022,000
Goodwill and acquired intangible assets impairment and amortization	6,063,000	9,710,000	12,127,000	19,422,000
Income tax benefit	(9,585,000)	198,978,000	90,126,000	358,138,000
Net income (loss)	(5,648,000)	337,818,000	169,046,000	577,958,000
Adjustment [Member]
"Core Earnings" adjustments to GAAP:
Net interest income after provisions for loan losses	107,000,000	135,000,000	233,000,000	283,000,000
Total other income (loss)	(521,000,000)	76,000,000	(780,000,000)	(5,000,000)
Goodwill and acquired intangible assets impairment and amortization	6,000,000	10,000,000	12,000,000	19,000,000
Total "Core Earnings" adjustments to GAAP	(420,000,000)	201,000,000	(559,000,000)	259,000,000
Income tax benefit	(154,000,000)	74,000,000	(208,000,000)	106,000,000
Net income (loss)	(266,000,000)	127,000,000	(351,000,000)	153,000,000
Adjustment [Member] | Net impact of derivative accounting [Member]
"Core Earnings" adjustments to GAAP:
Net interest income after provisions for loan losses	107,000,000	135,000,000	233,000,000	283,000,000
Total other income (loss)	(521,000,000)	76,000,000	(780,000,000)	(5,000,000)
Total "Core Earnings" adjustments to GAAP	(414,000,000)	211,000,000	(547,000,000)	278,000,000
Adjustment [Member] | Net impact of goodwill and acquired intangibles [Member]
"Core Earnings" adjustments to GAAP:
Goodwill and acquired intangible assets impairment and amortization	6,000,000	10,000,000	12,000,000	19,000,000
Total "Core Earnings" adjustments to GAAP	$ (6,000,000)	$ (10,000,000)	$ (12,000,000)	$ (19,000,000)