FAIR VALUE MEASUREMENTS (Details 2) (Level 2, USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Carrying Value
Fair Value And Carrying Value By Balance Sheet Grouping
Total debt	$ 3,318,711	$ 2,941,444
Carrying Value | Fixed Rate Debt
Fair Value And Carrying Value By Balance Sheet Grouping
Total debt	3,063,711	2,070,244
Carrying Value | Variable Rate Debt
Fair Value And Carrying Value By Balance Sheet Grouping
Total debt	255,000	871,200
Fair Value
Fair Value And Carrying Value By Balance Sheet Grouping
Total debt	3,403,634	3,074,862
Fair Value | Fixed Rate Debt
Fair Value And Carrying Value By Balance Sheet Grouping
Total debt	3,148,634	2,203,662
Fair Value | Variable Rate Debt
Fair Value And Carrying Value By Balance Sheet Grouping
Total debt	$ 255,000	$ 871,200