Note 5 - Loans - Age Analysis of Recorded Investment in Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Loans, past due	$ 22,820	$ 22,997
Loans, current	5,550,504	5,513,299
Total Loans	5,573,324	5,536,296
Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	4,721	6,913
Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due	3,248	1,740
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	14,851	14,344
Multi-family Residential Portfolio Segment [Member]
Loans, past due	2,692	4,636
Loans, current	2,253,755	2,264,412
Total Loans	2,256,447	2,269,048
Multi-family Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	683	1,887
Multi-family Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due		339
Multi-family Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	2,009	2,410
Commercial Real Estate Portfolio Segment [Member]
Loans, past due	3,630	1,758
Loans, current	1,525,371	1,540,789
Total Loans	1,529,001	1,542,547
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	786	379
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due	1,794
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	1,050	1,379
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member]
Loans, past due	2,237	2,253
Loans, current	579,812	575,488
Total Loans	582,049	577,741
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	1,212	1,003
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due		322
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	1,025	928
One-To-Four Family - Residential Portfolio Segment [Member]
Loans, past due	7,395	7,708
Loans, current	181,220	182,642
Total Loans	188,615	190,350
One-To-Four Family - Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	1,532	1,564
One-To-Four Family - Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due	155
One-To-Four Family - Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	5,708	6,144
Co-Operative Apartments Portfolio Segment [Member]
Loans, past due
Loans, current	7,903	8,498
Total Loans	7,903	8,498
Co-Operative Apartments Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due
Co-Operative Apartments Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due
Co-Operative Apartments Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due
Construction Portfolio Segment [Member]
Loans, past due	950	730
Loans, current	53,983	49,870
Total Loans	54,933	50,600
Construction Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due
Construction Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due		730
Construction Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	950
Small Business Administration Portfolio Segment [Member]
Loans, past due	1,227	2,109
Loans, current	13,961	13,101
Total Loans	15,188	15,210
Small Business Administration Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due		774
Small Business Administration Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due		68
Small Business Administration Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	1,227	1,267
Taxi Medallion Portfolio Segment [Member]
Loans, past due	768
Loans, current	3,123	4,539
Total Loans	3,891	4,539
Taxi Medallion Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due
Taxi Medallion Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due
Taxi Medallion Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	768
Commercial Business and Other Portfolio Segment [Member]
Loans, past due	3,921	3,803
Loans, current	931,376	873,960
Total Loans	935,297	877,763
Commercial Business and Other Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	508	1,306
Commercial Business and Other Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due	1,299	281
Commercial Business and Other Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	$ 2,114	$ 2,216