STOCK-BASED COMPENSATION - Stock options (Details) - Stock options - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Weighted-average assumptions utilized in determining the fair value of options
Risk-free interest rate (as a percent)		2.20%
Expected stock volatility (as a percent)		36.10%
Dividend yield (as a percent)		4.80%
Expected term (in years)		6 years
Options
Options outstanding at the beginning of the period (in shares)	3,499
Exercised (in shares)	(191)
Forfeited/Expired (in shares)	(9)
Option outstanding at the end of the period (in shares)	3,299
Options vested and expected to vest at the end of the period (in shares)	3,299
Exercisable at the end of the period (in shares)	2,497
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 58.62
Exercised (in dollars per share)	22.07
Forfeited/Expired (in dollars per share)	58.43
Outstanding at the end of the period (in dollars per share)	60.74
Vested and expected to vest at the end of the period (in dollars per share)	60.74
Exercisable at the end of the period (in dollars per share)	$ 60.23
Stock-Based Compensation
Outstanding at the end of the period (in years)	5 years 11 months 1 day
Vested and expected to vest (in years)	5 years 11 months 1 day
Exercisable at the end of the period (in years)	5 years 1 month 24 days
Outstanding at the end of the period, Aggregate Intrinsic Value (in dollars)	$ 2,269.0
Vested and expected to vest at end of the period, Aggregate Intrinsic Value (in dollars)	2,269.0
Exercisable at end of the period, Aggregate Intrinsic Value (in dollars)	$ 2,269.0