Fair Value Measurements (Fair Value Assets And Liabilities Measured On Recurring Basis) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	$ 3,257,360	$ 3,136,160
Total financial assets held at fair value	3,306,844	3,197,301
Total financial liabilities held at fair value	24,433	43,301
Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets	37,298	50,969
Derivative instruments - liabilities	24,433	43,172
Fed Fund futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - liabilities	141	125
Mortgage banking derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets	5,084	2,898
Investments held in Rabbi Trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets	5,604	5,741
Investments in private equity funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets	1,357	1,533
Visa swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - liabilities		4
U.S. Treasury Bills [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	200	200
Agency CMOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	1,003,897	1,310,006
Agency MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	1,338,192	1,142,280
CMBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	440,136	398,031
CLOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	278,008	88,540
Pooled trust preferred securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	30,215	26,207
Single issuer trust preferred securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	44,875	44,415
Corporate debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	112,671	118,199
Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	9,166	8,282
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	9,091	8,282
Derivative instruments - assets	141	0
Total financial assets held at fair value	14,836	14,023
Derivative instruments - liabilities	0	125
Total financial liabilities held at fair value		125
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets		0
Derivative instruments - liabilities		0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fed Fund futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - liabilities	141	125
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Mortgage banking derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets		0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Investments held in Rabbi Trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets	5,604	5,741
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Investments in private equity funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets		0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Visa swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - liabilities		0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | U.S. Treasury Bills [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	200	200
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Agency CMOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Agency MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | CMBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | CLOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	0	0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Pooled trust preferred securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Single issuer trust preferred securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Corporate debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	8,891	8,082
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	3,218,054	3,013,131
Derivative instruments - assets	37,298	50,969
Total financial assets held at fair value	3,260,436	3,066,998
Derivative instruments - liabilities	24,433	43,176
Total financial liabilities held at fair value	24,433	43,176
Significant Other Observable Inputs (Level 2) [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets	37,298	50,969
Derivative instruments - liabilities	24,433	43,172
Significant Other Observable Inputs (Level 2) [Member] | Fed Fund futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets	0
Derivative instruments - liabilities		0
Significant Other Observable Inputs (Level 2) [Member] | Mortgage banking derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets	5,084	2,898
Significant Other Observable Inputs (Level 2) [Member] | Investments held in Rabbi Trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets		0
Significant Other Observable Inputs (Level 2) [Member] | Investments in private equity funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets		0
Significant Other Observable Inputs (Level 2) [Member] | Visa swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - liabilities		4
Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasury Bills [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Significant Other Observable Inputs (Level 2) [Member] | Agency CMOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	1,003,897	1,310,006
Significant Other Observable Inputs (Level 2) [Member] | Agency MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	1,338,192	1,142,280
Significant Other Observable Inputs (Level 2) [Member] | CMBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	440,136	398,031
Significant Other Observable Inputs (Level 2) [Member] | CLOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	278,008	0
Significant Other Observable Inputs (Level 2) [Member] | Pooled trust preferred securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Significant Other Observable Inputs (Level 2) [Member] | Single issuer trust preferred securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	44,875	44,415
Significant Other Observable Inputs (Level 2) [Member] | Corporate debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	112,671	118,199
Significant Other Observable Inputs (Level 2) [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	275	200
Significant Unobservable Input (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	30,215	114,747
Derivative instruments - assets	0	0
Total financial assets held at fair value	31,572	116,280
Derivative instruments - liabilities	0	0
Total financial liabilities held at fair value		0
Significant Unobservable Input (Level 3) [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets		0
Derivative instruments - liabilities		0
Significant Unobservable Input (Level 3) [Member] | Fed Fund futures contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets	0
Derivative instruments - liabilities		0
Significant Unobservable Input (Level 3) [Member] | Mortgage banking derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets		0
Significant Unobservable Input (Level 3) [Member] | Investments held in Rabbi Trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets		0
Significant Unobservable Input (Level 3) [Member] | Investments in private equity funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - assets	1,357	1,533
Significant Unobservable Input (Level 3) [Member] | Visa swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative instruments - liabilities		0
Significant Unobservable Input (Level 3) [Member] | U.S. Treasury Bills [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Significant Unobservable Input (Level 3) [Member] | Agency CMOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Significant Unobservable Input (Level 3) [Member] | Agency MBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Significant Unobservable Input (Level 3) [Member] | CMBS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Significant Unobservable Input (Level 3) [Member] | CLOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	0	88,540
Significant Unobservable Input (Level 3) [Member] | Pooled trust preferred securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	30,215	26,207
Significant Unobservable Input (Level 3) [Member] | Single issuer trust preferred securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Significant Unobservable Input (Level 3) [Member] | Corporate debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		0
Significant Unobservable Input (Level 3) [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		$ 0