Investment Securities (Summary Of Investment Securities) (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Investment [Line Items]
Held-to-maturity, fair value	$ 727,908		$ 674,741
Held-to-maturity, Amortized cost	834,454		802,343
Held To Maturity Securities Gross Unrealized Gains	0
Held To Maturity Securities Gross Unrealized Gains Losses 1			0
Held To Maturity Securities Gross Unrealized Losses	56,605
Held To Maturity Securities Gross Unrealized Losses 1			45,434
Held-to-maturity, Carrying value	777,849		756,909
Available-for-sale debt securities, Amortized cost	3,578,968
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	58,145
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	560,255
Available-For-Sale Securities, Debt Securities, Net Carrying Amount	3,076,858
Available-for-sale debt securities, Estimated fair value	3,076,858		2,863,299
Available-for-sale Securities, Gross Unrealized Gain	58,327		72,296
Available-for-sale equity securities, Amortized cost			3,488,480
Gross Unrealized Gains on Debt Securities			72,102
Gross Unrealized Losses on AFS Debt Securities			697,283
Available-for-sale equity securities, Carrying value			2,863,299
Available-for-sale, Amortized cost	3,841,461		3,716,949
Available-for-sale, Gross unrealized losses, Recognized in OCI	565,899		697,935
Carrying value	3,333,889		3,091,310
Available-for-sale securities, Estimated fair value	3,333,889		3,091,310
Held-to-maturity Securities, Unrecognized Holding Gain		18,316	13,660
Held-to-maturity Securities, Unrecognized Holding Loss		68,257	95,828
amortized cost of investment securities	4,675,915		4,519,292
Gross Unrealized Gains of Investment Securities Recognized in OCI	58,327		72,296
Gross Unrealized Losses of Investment Securities Recognized in OCI	622,504		743,369
Carrying Value of Investment Securities	4,111,738		3,848,219
Estimated Fair Value of Investment Securities	4,061,797		3,766,051
Municipal Securities [Member]
Investment [Line Items]
Held-to-maturity, fair value	564,610		536,866
Held-to-maturity, Amortized cost	558,134		524,738
Held To Maturity Securities Gross Unrealized Gains	0
Held To Maturity Securities Gross Unrealized Gains Losses 1			0
Held To Maturity Securities Gross Unrealized Losses	0
Held To Maturity Securities Gross Unrealized Losses 1			0
Held-to-maturity, Carrying value	558,134		524,738
Available-for-sale debt securities, Amortized cost	64,694		75,344
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	1,509
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	1,034
Available-For-Sale Securities, Debt Securities, Net Carrying Amount	65,169		75,996
Available-for-sale debt securities, Estimated fair value	65,169		75,996
Available-for-sale Securities, Gross Unrealized Gain			2,622
Available-for-sale, Gross unrealized losses, Recognized in OCI			1,970
Held-to-maturity Securities, Unrecognized Holding Gain		11,537	12,837
Held-to-maturity Securities, Unrecognized Holding Loss		5,061	709
Trust Preferred Securities - Banks And Insurance [Member] | Asset-Backed Securities [Member]
Investment [Line Items]
Held-to-maturity, fair value	151,548		126,201
Held-to-maturity, Amortized cost	255,159		255,647
Held To Maturity Securities Gross Unrealized Gains	0
Held To Maturity Securities Gross Unrealized Gains Losses 1			0
Held To Maturity Securities Gross Unrealized Losses	54,432
Held To Maturity Securities Gross Unrealized Losses 1			42,964
Held-to-maturity, Carrying value	200,727		212,683
Available-for-sale debt securities, Amortized cost	1,521,628
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	14,391
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	534,123
Available-For-Sale Securities, Debt Securities, Net Carrying Amount	1,001,896
Available-for-sale debt securities, Estimated fair value	1,001,896
Available-for-sale Securities, Gross Unrealized Gain			16,687
Available-for-sale equity securities, Amortized cost			1,596,156
Available-for-sale equity securities, Carrying value			949,392
Available-for-sale, Gross unrealized losses, Recognized in OCI			663,451
Available-for-sale securities, Estimated fair value			949,392
Held-to-maturity Securities, Unrecognized Holding Gain		5,879	114
Held-to-maturity Securities, Unrecognized Holding Loss		55,058	86,596
Other [Member] | Asset-Backed Securities [Member]
Investment [Line Items]
Held-to-maturity, fair value	11,650		11,574
Held-to-maturity, Amortized cost	21,061		21,858
Held To Maturity Securities Gross Unrealized Gains	0
Held To Maturity Securities Gross Unrealized Gains Losses 1			0
Held To Maturity Securities Gross Unrealized Losses	2,173
Held To Maturity Securities Gross Unrealized Losses 1			2,470
Held-to-maturity, Carrying value	18,888		19,388
Available-for-sale debt securities, Amortized cost	18,496
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	406
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	2,788
Available-For-Sale Securities, Debt Securities, Net Carrying Amount	16,114
Available-for-sale debt securities, Estimated fair value	16,114
Available-for-sale Securities, Gross Unrealized Gain			701
Available-for-sale equity securities, Amortized cost			25,614
Available-for-sale equity securities, Carrying value			19,374
Available-for-sale, Gross unrealized losses, Recognized in OCI			6,941
Available-for-sale securities, Estimated fair value			19,374
Held-to-maturity Securities, Unrecognized Holding Gain		900	709
Held-to-maturity Securities, Unrecognized Holding Loss		8,138	8,523
Other Debt Securities [Member] | Asset-Backed Securities [Member]
Investment [Line Items]
Held-to-maturity, fair value	100		100
Held-to-maturity, Amortized cost	100		100
Held To Maturity Securities Gross Unrealized Gains	0
Held To Maturity Securities Gross Unrealized Gains Losses 1			0
Held To Maturity Securities Gross Unrealized Losses	0
Held To Maturity Securities Gross Unrealized Losses 1			0
Held-to-maturity, Carrying value	100		100
Held-to-maturity Securities, Unrecognized Holding Gain		0	0
Held-to-maturity Securities, Unrecognized Holding Loss		0	0
U.S. Treasury Securities [Member]
Investment [Line Items]
Available-for-sale debt securities, Amortized cost	39,908		104,313
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	136
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	0
Available-For-Sale Securities, Debt Securities, Net Carrying Amount	40,044		104,524
Available-for-sale debt securities, Estimated fair value	40,044		104,524
Available-for-sale Securities, Gross Unrealized Gain			211
Available-for-sale, Gross unrealized losses, Recognized in OCI			0
Agency Securities [Member]
Investment [Line Items]
Available-for-sale debt securities, Amortized cost	440,170		108,814
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	2,120
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	197
Available-For-Sale Securities, Debt Securities, Net Carrying Amount	442,093		112,657
Available-for-sale debt securities, Estimated fair value	442,093		112,657
Available-for-sale Securities, Gross Unrealized Gain			3,959
Available-for-sale, Gross unrealized losses, Recognized in OCI			116
Agency Guaranteed Mortgage-Backed Securities [Member]
Investment [Line Items]
Available-for-sale debt securities, Amortized cost	308,964		406,928
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	11,619
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	609
Available-For-Sale Securities, Debt Securities, Net Carrying Amount	319,974		425,510
Available-for-sale debt securities, Estimated fair value	319,974		425,510
Available-for-sale Securities, Gross Unrealized Gain			18,598
Available-for-sale, Gross unrealized losses, Recognized in OCI			16
Small Business Administration Loan-Backed Securities [Member]
Investment [Line Items]
Available-for-sale debt securities, Amortized cost	1,139,211		1,124,322
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	27,829
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	1,614
Available-For-Sale Securities, Debt Securities, Net Carrying Amount	1,165,426		1,152,928
Available-for-sale debt securities, Estimated fair value	1,165,426		1,152,928
Available-for-sale Securities, Gross Unrealized Gain			29,245
Available-for-sale, Gross unrealized losses, Recognized in OCI			639
Trust Preferred Securities - Real Estate Investment Trusts [Member] | Asset-Backed Securities [Member]
Investment [Line Items]
Available-for-sale debt securities, Amortized cost	39,391
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	0
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	19,874
Available-For-Sale Securities, Debt Securities, Net Carrying Amount	19,517
Available-for-sale debt securities, Estimated fair value	19,517
Available-for-sale Securities, Gross Unrealized Gain			0
Available-for-sale equity securities, Amortized cost			40,485
Available-for-sale equity securities, Carrying value			16,403
Available-for-sale, Gross unrealized losses, Recognized in OCI			24,082
Available-for-sale securities, Estimated fair value			16,403
Auction Rate Securities [Member] | Asset-Backed Securities [Member]
Investment [Line Items]
Available-for-sale debt securities, Amortized cost	6,506
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	135
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	16
Available-For-Sale Securities, Debt Securities, Net Carrying Amount	6,625
Available-for-sale debt securities, Estimated fair value	6,625
Available-for-sale Securities, Gross Unrealized Gain			79
Available-for-sale equity securities, Amortized cost			6,504
Available-for-sale equity securities, Carrying value			6,515
Available-for-sale, Gross unrealized losses, Recognized in OCI			68
Available-for-sale securities, Estimated fair value			6,515
Mutual Funds And Other [Member]
Investment [Line Items]
Available-for-sale Securities, Gross Unrealized Gain			194
Available-for-sale, Amortized cost			228,469
Available-for-sale, Gross unrealized losses, Recognized in OCI			652
Carrying value			228,011
Available-for-sale securities, Estimated fair value			228,011
Mutual Funds And Stock [Member]
Investment [Line Items]
Available-for-sale Securities, Gross Unrealized Gain	182
Available-for-sale, Amortized cost	262,493
Available-for-sale, Gross unrealized losses, Recognized in OCI	5,644
Carrying value	257,031
Available-for-sale securities, Estimated fair value	$ 257,031