Note 18 - Fair Value of Financial Instruments (Details) - Carrying Amounts and Estimated Fair Values of Selected Financial Instruments as Well as Assumptions Used in Estimating Fair Value (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Assets:
Carrying Amount, Assets	$ 5,077,013	$ 4,721,501
Liabilities:
Carrying Amount, Liabilities	4,620,766	4,288,969
Borrowings [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Fair Value, Liabilities	1,041,657	1,005,229
Borrowings [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities:
Fair Value, Liabilities	28,771	29,570
Borrowings [Member]
Liabilities:
Carrying Amount, Liabilities	1,056,492	1,012,122
Fair Value, Liabilities	1,070,428	1,034,799
Interest Rate Swaps [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Fair Value, Liabilities	2,649
Interest Rate Swaps [Member]
Liabilities:
Carrying Amount, Liabilities	2,649
Fair Value, Liabilities	2,649
Total Liabilities - Financial Instruments [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities:
Fair Value, Liabilities	2,202,775	2,111,825
Total Liabilities - Financial Instruments [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Fair Value, Liabilities	2,365,654	2,146,665
Total Liabilities - Financial Instruments [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities:
Fair Value, Liabilities	28,771	29,570
Total Liabilities - Financial Instruments [Member]
Liabilities:
Carrying Amount, Liabilities	4,567,739	4,244,902
Fair Value, Liabilities	4,597,200	4,288,060
Deposits [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities:
Fair Value, Liabilities	2,202,775	2,111,825
Deposits [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Fair Value, Liabilities	1,321,348	1,141,436
Deposits [Member]
Liabilities:
Carrying Amount, Liabilities	3,508,598	3,232,780
Fair Value, Liabilities	3,524,123	3,253,261
Fair Value, Inputs, Level 1 [Member] | Cash And Due From Banks [Member]
Assets:
Fair Value, Assets	34,265	33,485
Fair Value, Inputs, Level 1 [Member] | Total Assets - Financial Instruments [Member]
Assets:
Fair Value, Assets	34,265	33,485
Fair Value, Inputs, Level 2 [Member] | Collateralized Mortgage Backed Securities [Member]
Assets:
Fair Value, Assets	704,933	756,156
Fair Value, Inputs, Level 2 [Member] | Other Securities [Member]
Assets:
Fair Value, Assets	245,768	237,476
Fair Value, Inputs, Level 2 [Member] | FHLB - NY Stock [Member]
Assets:
Fair Value, Assets	46,924	46,025
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swaps [Member]
Assets:
Fair Value, Assets	84	2,081
Fair Value, Inputs, Level 2 [Member] | Total Assets - Financial Instruments [Member]
Assets:
Fair Value, Assets	997,709	1,041,738
Fair Value, Inputs, Level 3 [Member] | Other Securities [Member]
Assets:
Fair Value, Assets	22,609	24,158
Fair Value, Inputs, Level 3 [Member] | Loans [Member]
Assets:
Fair Value, Assets	3,871,087	3,502,792
Fair Value, Inputs, Level 3 [Member] | Other Real Estate Owned [Member]
Assets:
Fair Value, Assets	6,326	2,985
Fair Value, Inputs, Level 3 [Member] | Total Assets - Financial Instruments [Member]
Assets:
Fair Value, Assets	3,900,022	3,530,360
Fair Value, Inputs, Level 3 [Member] | Loans Held For Sale [Member]
Assets:
Fair Value, Assets		425
Cash And Due From Banks [Member]
Assets:
Carrying Amount, Assets	34,265	33,485
Fair Value, Assets	34,265	33,485
Collateralized Mortgage Backed Securities [Member]
Assets:
Carrying Amount, Assets	704,933	756,156
Fair Value, Assets	704,933	756,156
Other Securities [Member]
Assets:
Carrying Amount, Assets	268,377	261,634
Fair Value, Assets	268,377	261,634
Loans [Member]
Assets:
Carrying Amount, Assets	3,810,373	3,434,178
Fair Value, Assets	3,871,087	3,502,792
FHLB - NY Stock [Member]
Assets:
Carrying Amount, Assets	46,924	46,025
Fair Value, Assets	46,924	46,025
Interest Rate Swaps [Member]
Assets:
Carrying Amount, Assets	84	2,081
Fair Value, Assets	84	2,081
Other Real Estate Owned [Member]
Assets:
Carrying Amount, Assets	6,326	2,985
Fair Value, Assets	6,326	2,985
Total Assets - Financial Instruments [Member]
Assets:
Carrying Amount, Assets	4,871,282	4,536,969
Fair Value, Assets	4,931,996	4,605,583
Loans Held For Sale [Member]
Assets:
Carrying Amount, Assets		425
Fair Value, Assets		$ 425