LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Fixed-rate and Adjustable-Rate Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Fixed-rate (term to maturity):
Due in one year or less	$ 152,586	$ 183,004	$ 213,503
Due after one year through three years	176,372	171,724	231,148
Due after three years through five years	187,021	173,251	175,846
Due after five years through ten years	172,654	167,858	159,453
Due after ten years	445,872	473,927	477,495
Total fixed-rate loans	1,134,505	1,169,764	1,257,445
Adjustable-Rate (term to rate adjustment):
Due in one year or less	1,274,415	1,260,472	1,188,664
Due after one year through three years	253,048	275,223	387,588
Due after three years through five years	515,861	467,895	363,719
Due after five years through ten years	62,443	60,316	25,863
Due after ten years	49	2,044	6,383
Total adjustable-rate loans	2,105,816	2,065,950	1,972,217
Total loans outstanding	$ 3,240,321	$ 3,235,714	$ 3,229,662