PARENT COMPANY FINANCIAL INFORMATION (Details 3) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
INCOME      
Interest on interest-bearing deposits with the Bank $ 821 $ 893 $ 890
EXPENSES      
Interest expense 25,640 30,973 38,046
Other expenses 22,734 19,723 19,688
Income tax (benefit) expense 2,595 1,759 (1,913)
Net income 12,578 14,179 11,036
Beneficial Mutual Bancorp, Inc.
      
INCOME      
Interest on interest-bearing deposits with the Bank 153 369 393
Interest and dividends on investment securities   26 88
Interest on loan to the Bank     282
Realized gain on securities available-for-sale   1,112 130
Other income 15 16 15
Total income 168 1,523 908
EXPENSES      
Expenses paid to the Bank 149 104 104
Interest expense 503 552 512
Other expenses 1,058 445 796
Total expenses 1,710 1,101 1,412
(Loss) income before income tax (benefit) expense and equity in undistributed net income of affiliates (1,542) 422 (504)
Income tax (benefit) expense (540) 148 (177)
Equity in undistributed net income of the Bank 13,580 13,905 11,363
Net income $ 12,578 $ 14,179 $ 11,036