Investment Securities (Summary Of Investment Securities) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Schedule of Investments [Line Items]
Available-for-sale Securities, Gross Realized Gain (Loss)	$ (6,565)		$ 3,347		$ 3,823
Available for sale - Amortized cost	3,110,912		3,069,182
Available for sale - Gross unrealized gains, Recognized in OCI	57,645		98,467
Available-for-sale - Gross unrealized losses, Recognized in OCI	(61,626)		(31,489)
Available for sale - Fair value	3,106,931		3,136,160
Held-to-maturity Securities	3,358,721		3,107,529
Held-to-maturity - Gross unrealized gains, Not Recognized in OCI	73,409		157,781
Held-to-maturity - Gross unrealized losses, Not Recognized in OCI	(61,218)		(592)
Held to Maturity, Fair Value - Total debt securities	3,370,912		3,264,718
Total investment securities, Amortized cost	6,469,633		6,176,711
Total investment securities, Gross unrealized gains Recognized in OCI	57,645		98,467
Total investment securities, Gross unrealized losses Recognized in OCI	(61,626)		(31,489)
Total investment securities, Carrying value	6,465,652		6,243,689
Total investment securities, Gross unrealized gains, Not Recognized in OCI	73,409		157,781
Total investment securities, Gross unrealized losses, Not Recognized in OCI	(61,218)		(592)
Total investment securities, Fair Value	6,477,843		6,400,878
U.S. Treasury Bills [Member]
Schedule of Investments [Line Items]
Available for sale - Amortized cost	325		200
Available for sale - Gross unrealized gains, Recognized in OCI	0		0
Available-for-sale - Gross unrealized losses, Recognized in OCI	0		0
Available for sale - Fair value	325		200
Agency collateralized mortgage obligations (CMOs) [Member]
Schedule of Investments [Line Items]
Available for sale - Amortized cost	794,397		1,284,126
Available for sale - Gross unrealized gains, Recognized in OCI	14,383		25,972
Available-for-sale - Gross unrealized losses, Recognized in OCI	(1,868)		(92)
Available for sale - Fair value	806,912		1,310,006
Held-to-maturity Securities	365,081		500,369
Held-to-maturity - Gross unrealized gains, Not Recognized in OCI	10,135		16,643
Held-to-maturity - Gross unrealized losses, Not Recognized in OCI	(1,009)		(8)
Held to Maturity, Fair Value - Total debt securities	374,207		517,004
Agency mortage-backed securities (MBS) [Member]
Schedule of Investments [Line Items]
Available for sale - Amortized cost	1,265,276		1,121,941
Available for sale - Gross unrealized gains, Recognized in OCI	9,124		21,437
Available-for-sale - Gross unrealized losses, Recognized in OCI	(47,698)		(1,098)
Available for sale - Fair value	1,226,702		1,142,280
Held-to-maturity Securities	2,130,685		1,833,677
Held-to-maturity - Gross unrealized gains, Not Recognized in OCI	43,315		88,082
Held-to-maturity - Gross unrealized losses, Not Recognized in OCI	(53,188)		(474)
Held to Maturity, Fair Value - Total debt securities	2,120,812		1,921,285
Agency commercial mortgage-backed securities (ACMBS) [Member]
Schedule of Investments [Line Items]
Available for sale - Amortized cost	71,759
Available for sale - Gross unrealized gains, Recognized in OCI	0
Available-for-sale - Gross unrealized losses, Recognized in OCI	(782)
Available for sale - Fair value	70,977
Held-to-maturity Securities	115,995
Held-to-maturity - Gross unrealized gains, Not Recognized in OCI	44
Held-to-maturity - Gross unrealized losses, Not Recognized in OCI	(818)
Held to Maturity, Fair Value - Total debt securities	115,221
Commercial mortgage-backed securities (CMBS) [Member]
Schedule of Investments [Line Items]
Available for sale - Amortized cost	436,872		359,438
Available for sale - Gross unrealized gains, Recognized in OCI	28,398		42,086
Available-for-sale - Gross unrealized losses, Recognized in OCI	(996)		(3,493)
Available for sale - Fair value	464,274		398,031
Held-to-maturity Securities	290,057		199,810
Held-to-maturity - Gross unrealized gains, Not Recognized in OCI	8,635		18,324
Held-to-maturity - Gross unrealized losses, Not Recognized in OCI	(4,975)		0
Held to Maturity, Fair Value - Total debt securities	293,717		218,134
Collateralized Loan Obligations [Member]
Schedule of Investments [Line Items]
Available for sale - Amortized cost	357,326	[1]	88,765
Available for sale - Gross unrealized gains, Recognized in OCI	315	[1]	0
Available-for-sale - Gross unrealized losses, Recognized in OCI	(2,600)	[1]	(225)
Available for sale - Fair value	357,641	[1]	88,540
Pooled trust preferred securities [Member]
Schedule of Investments [Line Items]
Available for sale - Amortized cost	31,900	[2]	46,018	[3]
Available for sale - Gross unrealized gains, Recognized in OCI	0	[2]	0	[3]
Available-for-sale - Gross unrealized losses, Recognized in OCI	(3,410)	[2]	(19,811)	[3]
Available for sale - Fair value	28,490	[2]	26,207	[3]
Single issuer trust preferred securities [Member]
Schedule of Investments [Line Items]
Available for sale - Amortized cost	41,807		51,181
Available for sale - Gross unrealized gains, Recognized in OCI	0		0
Available-for-sale - Gross unrealized losses, Recognized in OCI	(6,872)		(6,766)
Available for sale - Fair value	34,935		44,415
Corporate debt securities [Member]
Schedule of Investments [Line Items]
Available for sale - Amortized cost	108,936		111,281
Available for sale - Gross unrealized gains, Recognized in OCI	4,155		6,918
Available-for-sale - Gross unrealized losses, Recognized in OCI	0		0
Available for sale - Fair value	113,091		118,199
Equity securities - financial institutions [Member]
Schedule of Investments [Line Items]
Available for sale - Amortized cost	2,314	[4]	6,232	[5]
Available for sale - Gross unrealized gains, Recognized in OCI	1,270	[4]	2,054	[5]
Available-for-sale - Gross unrealized losses, Recognized in OCI	0	[4]	(4)	[5]
Available for sale - Fair value	3,584	[4]	8,282	[5]
Municipal bonds and notes [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities	448,405		559,131
Held-to-maturity - Gross unrealized gains, Not Recognized in OCI	11,104		34,366
Held-to-maturity - Gross unrealized losses, Not Recognized in OCI	(1,228)		(110)
Held to Maturity, Fair Value - Total debt securities	458,281		593,387
Private Label MBS [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities	8,498		14,542
Held-to-maturity - Gross unrealized gains, Not Recognized in OCI	176		366
Held-to-maturity - Gross unrealized losses, Not Recognized in OCI	0		0
Held to Maturity, Fair Value - Total debt securities	$ 8,674		$ 14,908

[1] Amortized cost is net of $2.6 million of other-than-temporary impairment at December 31, 2013.

[2] Amortized cost is net of $14.0 million of other-than-temporary impairment at December 31, 2013

[3] Amortized cost is net of $10.5 million of credit related other-than-temporary impairment at December 31, 2012.

[4] Amortized cost is net of $20.4 million of other-than-temporary impairment at December 31, 2013.

[5] Amortized cost is net of $21.3 million of other-than-temporary impairment at December 31, 2012.