Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE MEASUREMENTS (Fair Value of Debt) (Details)

v3.5.0.2
FAIR VALUE MEASUREMENTS (Fair Value of Debt) (Details) - USD ($)
$ in Millions
Jun. 30, 2016
Dec. 31, 2015
Fixed Rate Debt With Noncontrolling Interest Partner [Member]    
Estimate of fair value not practicable [Abstract]    
Face amount of debt $ 36.3 $ 32.9
Level 2 [Member] | 7% Senior Notes due 2020 [Member]    
Debt Fair Value [Line Items]    
Interest rate, stated percentage 7.00% 7.00%
Estimated fair values of senior notes $ 443.1 $ 443.1
Level 2 [Member] | 5.375% Senior Notes due 2022 [Member]    
Debt Fair Value [Line Items]    
Interest rate, stated percentage 5.375% 5.375%
Estimated fair values of senior notes $ 253.8 $ 249.4
Level 2 [Member] | 2.5% Convertible Senior Notes Due 2019 [Member]    
Debt Fair Value [Line Items]    
Interest rate, stated percentage 2.50% 2.50%
Estimated fair values of convertible senior notes $ 285.3 $ 280.2