Derivative Financial Instruments (Remaining Contract Maturity Of Fair Value Of OTC Derivative Assets And Liabilities) (Details) (USD $)	Mar. 31, 2013
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	$ 166,170,000	[1],[2],[3]
OTC derivative assets having maturity period of 1 to 5 years	84,285,000	[1],[2],[3]
OTC derivative assets having maturity period of greater than 5 years	180,004,000	[1],[2],[3]
OTC derivative assets cross-maturity netting	(86,252,000)	[1],[2],[3],[4]
Total OTC derivative assets, net of cross-maturity netting	344,207,000	[1],[2],[3]
Cross product counterparty netting	(1,511,000)	[1],[2],[3]
Total OTC derivative assets included in Financial instruments owned	342,696,000	[1],[2],[3],[5]
OTC derivative liabilities having maturity period of 0 to 12 months	207,446,000	[3],[6],[7]
OTC derivative liabilities having maturity period of 1 to 5 years	169,298,000	[3],[6],[7]
OTC derivative liabilities having maturity period of greater than 5 years	210,771,000	[3],[6],[7]
OTC derivative liabilities cross-maturity netting	(86,252,000)	[3],[4],[6],[7]
Total OTC derivative liabilities, net of cross-maturity netting	501,263,000	[3],[6],[7]
Cross product counterparty netting	(1,511,000)	[3],[6],[7]
Total OTC derivative liabilities included in Trading liabilities	499,752,000	[3],[6],[7]
Exchange traded derivative assets and other credit enhancements	20,500,000
Cash collateral received	156,300,000
Exchange traded derivative liabilities and other credit enhancements	13,500,000
Cash collateral pledged	292,600,000
Commodity Swaps, Options And Forwards [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	61,023,000	[1],[2],[3]
OTC derivative assets having maturity period of 1 to 5 years	137,000	[1],[2],[3]
OTC derivative assets cross-maturity netting	(318,000)	[1],[2],[3],[4]
Total OTC derivative assets, net of cross-maturity netting	60,842,000	[1],[2],[3]
OTC derivative liabilities having maturity period of 0 to 12 months	107,646,000	[3],[6],[7]
OTC derivative liabilities having maturity period of 1 to 5 years	108,000	[3],[6],[7]
OTC derivative liabilities cross-maturity netting	(318,000)	[3],[4],[6],[7]
Total OTC derivative liabilities, net of cross-maturity netting	107,436,000	[3],[6],[7]
Credit Default Swaps [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 1 to 5 years	3,844,000	[1],[2],[3]
Total OTC derivative assets, net of cross-maturity netting	3,844,000	[1],[2],[3]
OTC derivative liabilities having maturity period of 0 to 12 months	238,000	[3],[6],[7]
OTC derivative liabilities having maturity period of 1 to 5 years	7,014,000	[3],[6],[7]
Total OTC derivative liabilities, net of cross-maturity netting	7,252,000	[3],[6],[7]
Equity Options [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	1,622,000	[1],[2],[3]
Total OTC derivative assets, net of cross-maturity netting	1,622,000	[1],[2],[3]
OTC derivative liabilities having maturity period of 0 to 12 months	3,148,000	[3],[6],[7]
Total OTC derivative liabilities, net of cross-maturity netting	3,148,000	[3],[6],[7]
Total Return Swaps [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	1,277,000	[1],[2],[3]
Total OTC derivative assets, net of cross-maturity netting	1,277,000	[1],[2],[3]
OTC derivative liabilities having maturity period of 0 to 12 months	6,248,000	[3],[6],[7]
Total OTC derivative liabilities, net of cross-maturity netting	6,248,000	[3],[6],[7]
Foreign Currency Forwards, Swaps And Options [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	82,784,000	[1],[2],[3]
OTC derivative assets having maturity period of 1 to 5 years	32,781,000	[1],[2],[3]
OTC derivative assets cross-maturity netting	(8,301,000)	[1],[2],[3],[4]
Total OTC derivative assets, net of cross-maturity netting	107,264,000	[1],[2],[3]
OTC derivative liabilities having maturity period of 0 to 12 months	73,554,000	[3],[6],[7]
OTC derivative liabilities having maturity period of 1 to 5 years	31,197,000	[3],[6],[7]
OTC derivative liabilities cross-maturity netting	(8,301,000)	[3],[4],[6],[7]
Total OTC derivative liabilities, net of cross-maturity netting	96,450,000	[3],[6],[7]
Fixed Income Forwards [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of greater than 5 years	447,000	[1],[2],[3]
Total OTC derivative assets, net of cross-maturity netting	447,000	[1],[2],[3]
Interest Rate Swap [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	19,464,000	[1],[2],[3]
OTC derivative assets having maturity period of 1 to 5 years	47,523,000	[1],[2],[3]
OTC derivative assets having maturity period of greater than 5 years	179,557,000	[1],[2],[3]
OTC derivative assets cross-maturity netting	(77,633,000)	[1],[2],[3],[4]
Total OTC derivative assets, net of cross-maturity netting	168,911,000	[1],[2],[3]
OTC derivative liabilities having maturity period of 0 to 12 months	16,612,000	[3],[6],[7]
OTC derivative liabilities having maturity period of 1 to 5 years	130,979,000	[3],[6],[7]
OTC derivative liabilities having maturity period of greater than 5 years	210,771,000	[3],[6],[7]
OTC derivative liabilities cross-maturity netting	(77,633,000)	[3],[4],[6],[7]
Total OTC derivative liabilities, net of cross-maturity netting	$ 280,729,000	[3],[6],[7]

[1] At March 31, 2013, we held exchange traded derivative assets and other credit enhancements with a fair value of $20.5 million, which are not included in this table.

[2] OTC derivative assets in the table above are gross of collateral received. OTC derivative assets are recorded net of collateral received in the Consolidated Statements of Financial Condition. At March 31, 2013 cash collateral received was $156.3 million.

[3] Derivative fair values include counterparty netting within product category.

[4] Amounts represent the netting of receivable balances with payable balances for the same counterparty within product category across maturity categories.

[5] We utilize the credit ratings of external rating agencies when available. When external credit ratings are not available, we utilize internal credit ratings determined by our Credit Risk Management. Credit ratings determined by Credit Risk Management use methodologies that produce ratings generally consistent with those produced by external rating agencies.

[6] At March 31, 2013, we held exchange traded derivative liabilities and other credit enhancements with a fair value of $13.5 million, which are not included in this table.

[7] OTC derivative liabilities in the table above are gross of collateral pledged. OTC derivative liabilities are recorded net of collateral pledged in the Consolidated Statements of Financial Condition. At March 31, 2013, cash collateral pledged was $292.6 million.