BORROWINGS (Long-Term Debt) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Total Long-Term Borrowings	$ 188,685	$ 153,906
Wholesale Repurchase Agreements [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	50,000	50,000
Junior Subordinated Debentures [Member] | Capital Trust V Preferred Securities Due in 2037 [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	51,547	51,547
Junior Subordinated Debentures [Member] | Slades Ferry Trust I Preferred Securities Due in 2034 [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	10,310	10,310
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust I Securities Due in 2034 [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	5,258	5,258
Junior Subordinated Debentures [Member] | Central Bancorp Capital Trust II Securities Due in 2037 [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	6,570	6,791
Subordinated Debentures [Member] | Subordinated Debentures Due August 27, 2018 [Member]
Debt Instrument [Line Items]
Total Long-Term Borrowings	$ 65,000	$ 30,000