CASH AND CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Composition of cash and cash equivalents
Cash and amounts due from banks	$ 693,387	$ 933,050
Cash equivalents:
Money market funds	605	3,526
Other short-term investments	201,828	386,530
Total cash and cash equivalents	895,820	1,323,106	1,431,185	1,333,949
Short-term investments
Balance at end of year	257,473	366,378
Average balance outstanding during the year	334,049	242,937
Maximum balance outstanding at any month-end	$ 384,375	$ 367,283
Weighted average interest rate at end of year (as a percent)	3.23%	2.64%