Investment Securities (Summary Of Gross Unrealized Losses Not Considered OTTI) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013 holding		Dec. 31, 2012 holding
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	$ 1,243,746		$ 405,620
Available for sale, Unrealized Losses - Less Than Twelve Months	(32,842)		(1,436)
Available for sale, Fair Value - Twelve Months or Longer	186,135		91,531
Available for sale, Unrealized Losses - Twelve Months or Longer	(19,707)		(30,053)
Available for sale, Number of Holdings - Total	133		54
Available for sale, Fair Value - Total	1,429,881		497,151
Available for sale, Unrealized Losses - Total	(52,549)		(31,489)
Held-to-maturity, Fair Value - Less Than Twelve Months	1,148,855		185,788
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(39,229)		(533)
Held-to-maturity, Fair Value - Twelve Months or Longer	43,839		2,858
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	(1,866)		(59)
Held-to-maturity, Number of Holdings - Total	120		24
Held-to-maturity, Fair Value - Total	1,192,694		188,646
Held-to-maturity, Unrealized Losses - Total	(41,095)		(592)
Total investment securities, Fair Value - Less Than Twelve Months	2,392,601		591,408
Total investment securities - Unrealized Losses - Less Than Twelve Months	72,071		1,969
Total investment securities - Fair Value - Twelve Months or Longer	229,974		94,389
Total investment securities, Unrealized Losses - Twelve Months or Longer	(21,573)		(30,112)
Total investment securities, Number of Holdings - Total	253		78
Total investment securities - Fair Value - Total	2,622,575		685,797
Total investment securities - Unrealized Losses - Total	(93,644)		(32,081)
Agency CMOs [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	90,774		69,936
Available for sale, Unrealized Losses - Less Than Twelve Months	(1,255)		(92)
Available for sale, Fair Value - Twelve Months or Longer	9,935		0
Available for sale, Unrealized Losses - Twelve Months or Longer	(94)
Available for sale, Number of Holdings - Total	6		4
Available for sale, Fair Value - Total	100,709		69,936
Available for sale, Unrealized Losses - Total	(1,349)		(92)
Held-to-maturity, Fair Value - Less Than Twelve Months	29,770		18,741
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(492)		(8)
Held-to-maturity, Fair Value - Twelve Months or Longer	0
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	0
Held-to-maturity, Number of Holdings - Total	2		1
Held-to-maturity, Fair Value - Total	29,770		18,741
Held-to-maturity, Unrealized Losses - Total	(492)		(8)
Agency MBS [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	880,443		275,818
Available for sale, Unrealized Losses - Less Than Twelve Months	(29,177)		(1,098)
Available for sale, Fair Value - Twelve Months or Longer	106,834
Available for sale, Unrealized Losses - Twelve Months or Longer	(5,239)
Available for sale, Number of Holdings - Total	92		28
Available for sale, Fair Value - Total	987,277		275,818
Available for sale, Unrealized Losses - Total	(34,416)		(1,098)
Held-to-maturity, Fair Value - Less Than Twelve Months	1,008,677		161,057
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(34,002)		(474)
Held-to-maturity, Fair Value - Twelve Months or Longer	41,673
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	(1,830)
Held-to-maturity, Number of Holdings - Total	72		12
Held-to-maturity, Fair Value - Total	1,050,350		161,057
Held-to-maturity, Unrealized Losses - Total	(35,832)		(474)
CMBS [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	51,274		14,947
Available for sale, Unrealized Losses - Less Than Twelve Months	(1,032)		(17)
Available for sale, Fair Value - Twelve Months or Longer			20,909
Available for sale, Unrealized Losses - Twelve Months or Longer			(3,476)
Available for sale, Number of Holdings - Total	6		2
Available for sale, Fair Value - Total	51,274		35,856
Available for sale, Unrealized Losses - Total	(1,032)		(3,493)
Held-to-maturity, Fair Value - Less Than Twelve Months	77,145
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(4,028)
Held-to-maturity, Fair Value - Twelve Months or Longer
Held-to-maturity, Unrealized Losses, Twelve Months or Longer
Held-to-maturity, Number of Holdings - Total	8
Held-to-maturity, Fair Value - Total	77,145
Held-to-maturity, Unrealized Losses - Total	(4,028)		0
CLOs [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	217,355		44,775
Available for sale, Unrealized Losses - Less Than Twelve Months	(1,126)		(225)
Available for sale, Fair Value - Twelve Months or Longer	0		0
Available for sale, Unrealized Losses - Twelve Months or Longer	0		0
Available for sale, Number of Holdings - Total	14		2
Available for sale, Fair Value - Total	217,355		44,775
Available for sale, Unrealized Losses - Total	(1,126)		(225)
Pooled trust preferred securities [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months			0
Available for sale, Unrealized Losses - Less Than Twelve Months
Available for sale, Fair Value - Twelve Months or Longer	29,964		26,207
Available for sale, Unrealized Losses - Twelve Months or Longer	(6,617)		(19,811)
Available for sale, Number of Holdings - Total	6		8
Available for sale, Fair Value - Total	29,964		26,207
Available for sale, Unrealized Losses - Total	(6,617)	[1]	(19,811)	[2]
Single issuer trust preferred securities [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	3,900		0
Available for sale, Unrealized Losses - Less Than Twelve Months	(252)
Available for sale, Fair Value - Twelve Months or Longer	39,402		44,415
Available for sale, Unrealized Losses - Twelve Months or Longer	(7,757)		(6,766)
Available for sale, Number of Holdings - Total	9		9
Available for sale, Fair Value - Total	43,302		44,415
Available for sale, Unrealized Losses - Total	(8,009)		(6,766)
Equity securities - financial institutions [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months			144
Available for sale, Unrealized Losses - Less Than Twelve Months			(4)
Available for sale, Fair Value - Twelve Months or Longer
Available for sale, Unrealized Losses - Twelve Months or Longer
Available for sale, Number of Holdings - Total			1
Available for sale, Fair Value - Total			144
Available for sale, Unrealized Losses - Total	0	[3]	(4)	[4]
Municipal bonds and notes [Member]
Schedule of Investments [Line Items]
Held-to-maturity, Fair Value - Less Than Twelve Months	33,263		5,990
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(707)		(51)
Held-to-maturity, Fair Value - Twelve Months or Longer	2,166		2,858
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	(36)		(59)
Held-to-maturity, Number of Holdings - Total	38		11
Held-to-maturity, Fair Value - Total	35,429		8,848
Held-to-maturity, Unrealized Losses - Total	$ (743)		$ (110)

[1] Amortized cost is net of $9.4 million of credit related other-than-temporary impairment at September 30, 2013.

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

[3] Amortized cost is net of $21.3 million of other-than-temporary impairment at September 30, 2013.

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