Note 10 - Fair Value of Financial Instruments (Details) - Carrying Amounts and Estimated Fair Values of Selected Financial Instruments (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Assets:
Carrying Value	$ 4,853,812	$ 4,721,501
Liabilities:
Carrying Value	4,393,305	4,288,969
Cash and due from banks [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Fair Value	36,982	33,485
Cash and due from banks [Member]
Assets:
Carrying Value	36,982	33,485
Fair Value	36,982	33,485
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Fair Value	770,545	756,156
Collateralized Mortgage Backed Securities [Member]
Assets:
Carrying Value	770,545	756,156
Fair Value	770,545	756,156
Other securities [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Fair Value	264,184	237,476
Other securities [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Fair Value	23,953	24,158
Other securities [Member]
Assets:
Carrying Value	288,137	261,634
Fair Value	288,137	261,634
Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Fair Value	3,607,781	3,502,792
Loans [Member]
Assets:
Carrying Value	3,532,537	3,434,178
Fair Value	3,607,781	3,502,792
FHLB-NY stock [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Fair Value	51,407	46,025
FHLB-NY stock [Member]
Assets:
Carrying Value	51,407	46,025
Fair Value	51,407	46,025
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Fair Value	178	2,081
Liabilities:
Fair Value	254
Interest Rate Swap [Member]
Assets:
Carrying Value	178	2,081
Fair Value	178	2,081
Liabilities:
Carrying Value	254
Fair Value	254
Other real estate owned [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Fair Value	1,346	2,985
Other real estate owned [Member]
Assets:
Carrying Value	1,346	2,985
Fair Value	1,346	2,985
Total Assets, Financial Instruments [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Fair Value	36,982	33,485
Total Assets, Financial Instruments [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Fair Value	1,086,314	1,041,738
Total Assets, Financial Instruments [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Fair Value	3,633,080	3,530,360
Total Assets, Financial Instruments [Member]
Assets:
Carrying Value	4,681,132	4,536,969
Fair Value	4,756,376	4,605,583
Total Liabilities, Financial Instruments [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities:
Fair Value	2,079,074	2,111,825
Total Liabilities, Financial Instruments [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Fair Value	2,283,052	2,146,665
Total Liabilities, Financial Instruments [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities:
Fair Value	29,388	29,570
Total Liabilities, Financial Instruments [Member]
Liabilities:
Carrying Value	4,351,427	4,244,902
Fair Value	4,391,514	4,288,060
Loans Held For Sale [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Fair Value		425
Loans Held For Sale [Member]
Assets:
Carrying Value		425
Fair Value		425
Deposits [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities:
Fair Value	2,079,074	2,111,825
Deposits [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Fair Value	1,176,218	1,141,436
Deposits [Member]
Liabilities:
Carrying Value	3,238,971	3,232,780
Fair Value	3,255,292	3,253,261
Borrowings [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Fair Value	1,106,580	1,005,229
Borrowings [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities:
Fair Value	29,388	29,570
Borrowings [Member]
Liabilities:
Carrying Value	1,112,202	1,012,122
Fair Value	$ 1,135,968	$ 1,034,799