Derivative Financial Instruments (Remaining Contract Maturity Of Fair Value Of OTC Derivative Assets And Liabilities) (Details) $ in Thousands	Mar. 31, 2016 USD ($)
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	$ 219,752
OTC derivative assets having maturity period of 1 to 5 years	230,189
OTC derivative assets having maturity period of greater than 5 years	113,854
OTC derivative assets cross-maturity netting	(84,471)
Total OTC derivative assets, net of cross-maturity netting	479,324
Cross product counterparty netting	(6,972)
Total OTC derivative assets included in Trading assets	472,352
OTC derivative liabilities having maturity period of 0 to 12 months	168,224
OTC derivative liabilities having maturity period of 1 to 5 years	148,839
OTC derivative liabilities having maturity period of greater than 5 years	128,905
OTC derivative liabilities cross-maturity netting	(84,471)
Total OTC derivative liabilities, net of cross-maturity netting	361,497
Cross product counterparty netting	(6,972)
Total OTC derivative liabilities included in Trading liabilities	354,525
Exchange traded derivative assets and other credit agreements	36,100
Cash collateral received	169,400
Exchange traded derivative liabilities and other credit agreements	170,000
Cash collateral pledged	197,800
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	6,725
OTC derivative assets having maturity period of 1 to 5 years	11,454
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	0
Total OTC derivative assets, net of cross-maturity netting	18,179
OTC derivative liabilities having maturity period of 0 to 12 months	2,124
OTC derivative liabilities having maturity period of 1 to 5 years	0
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	0
Total OTC derivative liabilities, net of cross-maturity netting	2,124
Equity 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	35,094
OTC derivative assets having maturity period of 1 to 5 years	2,870
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	0
Total OTC derivative assets, net of cross-maturity netting	37,964
OTC derivative liabilities having maturity period of 0 to 12 months	7,929
OTC derivative liabilities having maturity period of 1 to 5 years	20,068
OTC derivative liabilities having maturity period of greater than 5 years	617
OTC derivative liabilities cross-maturity netting	0
Total OTC derivative liabilities, net of cross-maturity netting	28,614
Credit Default 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	0
OTC derivative assets having maturity period of 1 to 5 years	6,472
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	(85)
Total OTC derivative assets, net of cross-maturity netting	6,387
OTC derivative liabilities having maturity period of 0 to 12 months	0
OTC derivative liabilities having maturity period of 1 to 5 years	8,421
OTC derivative liabilities having maturity period of greater than 5 years	1,094
OTC derivative liabilities cross-maturity netting	(85)
Total OTC derivative liabilities, net of cross-maturity netting	9,430
Total Return 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	24,628
OTC derivative assets having maturity period of 1 to 5 years	297
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	(215)
Total OTC derivative assets, net of cross-maturity netting	24,710
OTC derivative liabilities having maturity period of 0 to 12 months	16,379
OTC derivative liabilities having maturity period of 1 to 5 years	4,124
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	(215)
Total OTC derivative liabilities, net of cross-maturity netting	20,288
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	69,199
OTC derivative assets having maturity period of 1 to 5 years	20,257
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	(8,067)
Total OTC derivative assets, net of cross-maturity netting	81,389
OTC derivative liabilities having maturity period of 0 to 12 months	86,249
OTC derivative liabilities having maturity period of 1 to 5 years	14,085
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	(8,067)
Total OTC derivative liabilities, net of cross-maturity netting	92,267
Fixed Income Forwards [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative liabilities having maturity period of 0 to 12 months	7,405
OTC derivative liabilities having maturity period of 1 to 5 years	0
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	0
Total OTC derivative liabilities, net of cross-maturity netting	7,405
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	84,106
OTC derivative assets having maturity period of 1 to 5 years	188,839
OTC derivative assets having maturity period of greater than 5 years	113,854
OTC derivative assets cross-maturity netting	(76,104)
Total OTC derivative assets, net of cross-maturity netting	310,695
OTC derivative liabilities having maturity period of 0 to 12 months	48,138
OTC derivative liabilities having maturity period of 1 to 5 years	102,141
OTC derivative liabilities having maturity period of greater than 5 years	127,194
OTC derivative liabilities cross-maturity netting	(76,104)
Total OTC derivative liabilities, net of cross-maturity netting	$ 201,369