FAIR VALUE - Items Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Total
Cash equivalents:
Derivative assets	$ 2.5	$ 4.0
Total assets	145.7	198.7
Liabilities:
Derivative liabilities	2.1	0.9
Total liabilities	42.8	41.5
Total | Diversified investments associated with the Executive Stock Unit Program (ESUP)
Cash equivalents:
Diversified investments associated with the Executive Stock Unit Program (ESUP)	40.7	41.0
Total | Liabilities associated with the ESUP
Liabilities:
Liabilities associated with the ESUP	40.7	40.6
Total | Bank time deposits with original maturities of three months or less
Cash equivalents:
Bank time deposits with original maturities of three months or less	102.5	153.7
Level 1
Cash equivalents:
Derivative assets	0.0	0.0
Total assets	40.7	41.0
Liabilities:
Derivative liabilities	0.0	0.0
Total liabilities	40.7	40.6
Level 1 | Diversified investments associated with the Executive Stock Unit Program (ESUP)
Cash equivalents:
Diversified investments associated with the Executive Stock Unit Program (ESUP)	40.7	41.0
Level 1 | Liabilities associated with the ESUP
Liabilities:
Liabilities associated with the ESUP	40.7	40.6
Level 1 | Bank time deposits with original maturities of three months or less
Cash equivalents:
Bank time deposits with original maturities of three months or less	0.0	0.0
Level 2
Cash equivalents:
Derivative assets	2.5	4.0
Total assets	105.0	157.7
Liabilities:
Derivative liabilities	2.1	0.9
Total liabilities	2.1	0.9
Level 2 | Diversified investments associated with the Executive Stock Unit Program (ESUP)
Cash equivalents:
Diversified investments associated with the Executive Stock Unit Program (ESUP)	0.0	0.0
Level 2 | Liabilities associated with the ESUP
Liabilities:
Liabilities associated with the ESUP	0.0	0.0
Level 2 | Bank time deposits with original maturities of three months or less
Cash equivalents:
Bank time deposits with original maturities of three months or less	102.5	153.7
Level 3
Cash equivalents:
Derivative assets	0.0	0.0
Total assets	0.0	0.0
Liabilities:
Derivative liabilities	0.0	0.0
Total liabilities	0.0	0.0
Level 3 | Diversified investments associated with the Executive Stock Unit Program (ESUP)
Cash equivalents:
Diversified investments associated with the Executive Stock Unit Program (ESUP)	0.0	0.0
Level 3 | Liabilities associated with the ESUP
Liabilities:
Liabilities associated with the ESUP	0.0	0.0
Level 3 | Bank time deposits with original maturities of three months or less
Cash equivalents:
Bank time deposits with original maturities of three months or less	$ 0.0	$ 0.0