Note 14 - Regulatory Capital (Details) - Summary of the Bank's Compliance (USD $) In Thousands, unless otherwise specified	Dec. 30, 2014
Commercial Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier I (leverage) capital, capital level, amount	$ 466,475
Tier I (leverage) capital, capital level, percent of assets	9.62%
Tier I (leverage) capital, requirement to be well capitalized, amount	242,485
Tier I (leverage) capital, requirement to be well capitalized, percent of assets	5.00%
Tier I (leverage) capital, excess, amount	223,990
Tier I (leverage) capital, excess, percent of assets	4.62%
Tier I risk-based capital, capital level, amount	466,475
Tier I risk-based capital, capital level, percent of assets	14.37%
Tier I risk-based capital, requirement to be well capitalized, amount	194,730
Tier I risk-based capital, requirement to be well capitalized, percent of assets	6.00%
Tier I risk-based capital, excess, amount	271,745
Tier I risk-based capital, excess, percent of assets	8.37%
Total risk-based capital, capital level, amount	494,819
Total risk-based capital, capital level, percent of assets	15.25%
Total risk-based capital, requirement to be well capitalized, amount	324,549
Total risk-based capital, requirement to be well capitalized, percent of assets	10.00%
Total risk-based capital, excess, amount	170,270
Total risk-based capital, excess, percent of assets	5.25%
Holding Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier I (leverage) capital, capital level, amount	469,670
Tier I (leverage) capital, capital level, percent of assets	9.70%
Tier I (leverage) capital, requirement to be well capitalized, amount	242,190
Tier I (leverage) capital, requirement to be well capitalized, percent of assets	5.00%
Tier I (leverage) capital, excess, amount	227,480
Tier I (leverage) capital, excess, percent of assets	4.70%
Tier I risk-based capital, capital level, amount	469,670
Tier I risk-based capital, capital level, percent of assets	14.50%
Tier I risk-based capital, requirement to be well capitalized, amount	194,373
Tier I risk-based capital, requirement to be well capitalized, percent of assets	6.00%
Tier I risk-based capital, excess, amount	275,297
Tier I risk-based capital, excess, percent of assets	8.50%
Total risk-based capital, capital level, amount	498,014
Total risk-based capital, capital level, percent of assets	15.37%
Total risk-based capital, requirement to be well capitalized, amount	323,956
Total risk-based capital, requirement to be well capitalized, percent of assets	10.00%
Total risk-based capital, excess, amount	$ 174,058
Total risk-based capital, excess, percent of assets	5.37%