Note 10 - Fair Value of Financial Instruments (Detail) - Carrying amounts and estimated fair values of selected financial instruments: (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Assets:
Assets, Carrying Amount	$ 4,476,513	$ 4,451,416
Liabilities:
Liabilities, Carrying Amount	4,032,630	4,009,051
Borrowings [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Liabilities, Fair Value	882,062	968,147
Borrowings [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities:
Liabilities, Fair Value	23,922	23,922
Borrowings [Member]
Liabilities:
Liabilities, Carrying Amount	868,364	948,405
Liabilities, Fair Value	905,984	992,069
Interest rate swaps [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Liabilities, Fair Value	1,138	1,922
Interest rate swaps [Member]
Liabilities:
Liabilities, Carrying Amount	1,138	1,922
Liabilities, Fair Value	1,138	1,922
Total Liabilities, Financial Instruments [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities:
Liabilities, Fair Value	1,905,746	1,761,964
Total Liabilities, Financial Instruments [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Liabilities, Fair Value	2,118,722	2,265,257
Total Liabilities, Financial Instruments [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities:
Liabilities, Fair Value	23,922	23,922
Total Liabilities, Financial Instruments [Member]
Liabilities:
Liabilities, Carrying Amount	3,976,154	3,965,520
Liabilities, Fair Value	4,048,390	4,051,143
Cash and due from banks [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Assets, Fair Value	46,046	40,425
Cash and due from banks [Member]
Assets:
Assets, Carrying Amount	46,046	40,425
Assets, Fair Value	46,046	40,425
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Assets, Fair Value	740,940	696,638
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Assets, Fair Value	23,761	23,475
Collateralized Mortgage Backed Securities [Member]
Assets:
Assets, Carrying Amount	764,701	720,113
Assets, Fair Value	764,701	720,113
Other securities [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Assets, Fair Value	218,788	213,374
Other securities [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Assets, Fair Value	16,805	16,079
Other securities [Member]
Assets:
Assets, Carrying Amount	235,593	229,453
Assets, Fair Value	235,593	229,453
Loans Held For Sale [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Assets, Fair Value	9,907	5,313
Loans Held For Sale [Member]
Assets:
Assets, Carrying Amount	9,907	5,313
Assets, Fair Value	9,907	5,313
Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Assets, Fair Value	3,365,486	3,416,313
Loans [Member]
Assets:
Assets, Carrying Amount	3,201,197	3,234,121
Assets, Fair Value	3,365,486	3,416,313
FHLB-NY stock [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Assets, Fair Value	38,686	42,337
FHLB-NY stock [Member]
Assets:
Assets, Carrying Amount	38,686	42,337
Assets, Fair Value	38,686	42,337
Interest rate caps [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Assets, Fair Value	16	19
Interest rate caps [Member]
Assets:
Assets, Carrying Amount	16	19
Assets, Fair Value	16	19
Interest rate swaps [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Assets, Fair Value	51	3
Interest rate swaps [Member]
Assets:
Assets, Carrying Amount	51	3
Assets, Fair Value	51	3
Other real estate owned [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Assets, Fair Value	2,189	5,278
Other real estate owned [Member]
Assets:
Assets, Carrying Amount	2,189	5,278
Assets, Fair Value	2,189	5,278
Total Assets, Financial Instruments [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Assets, Fair Value	46,046	40,425
Total Assets, Financial Instruments [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Assets, Fair Value	998,481	952,371
Total Assets, Financial Instruments [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Assets, Fair Value	3,418,148	3,466,458
Total Assets, Financial Instruments [Member]
Assets:
Assets, Carrying Amount	4,298,386	4,277,062
Assets, Fair Value	4,462,675	4,459,254
Fair Value, Inputs, Level 1 [Member] | Deposits [Member]
Liabilities:
Liabilities, Fair Value	1,905,746	1,761,964
Fair Value, Inputs, Level 2 [Member] | Deposits [Member]
Liabilities:
Liabilities, Fair Value	1,235,522	1,295,188
Deposits [Member]
Liabilities:
Liabilities, Carrying Amount	3,106,652	3,015,193
Liabilities, Fair Value	$ 3,141,268	$ 3,057,152