INVESTMENT SECURITIES (Details 4) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Dec. 31, 2012
Available-for-sale, amortized cost    
Due in one year or less, amortized cost $ 4,241 $ 5,635
Due after one year through five years, amortized cost 8,016 6,415
Due after five years through ten years, amortized cost 49,623 61,677
Due after ten years, amortized cost 16,693 38,459
Mortgage-backed securities, amortized cost 945,310 1,104,765
Money market and mutual funds, amortized cost 18,325 20,925
Available-for-sale securities, amortized cost 1,042,208 1,237,876
Available-for-sale, fair value    
Due in one year or less, fair value 4,286 5,696
Due after one year through five years, fair value 8,328 6,643
Due after five years through ten years, fair value 50,659 64,402
Due after ten years, fair value 17,085 38,546
Mortgage-backed securities, fair value 935,546 1,131,135
Money market and mutual funds, fair value 18,276 21,069
Investment securities available-for-sale, estimated fair value 1,034,180 1,267,491
Held-to-maturity, amortized cost    
Due in one year or less, amortized cost 2,540 4,142
Due after one year through five years, amortized cost 2,490 2,850
Due after five years through ten years, amortized cost 380 505
Mortgage-backed securities, amortized cost 523,419 469,701
Held-to-maturity debt securities, amortized cost 528,829 477,198
Held-to-maturity, fair value    
Due in one year or less, fair value 2,573 4,177
Due after one year through five years, fair value 2,543 2,913
Due after five years through ten years, fair value 430 599
Mortgage-backed securities, fair value 509,087 479,618
Investment securities held-to-maturity, estimated fair value $ 514,633 $ 487,307