EQUITY - NARRATIVE (Details) € in Millions	3 Months Ended		12 Months Ended		108 Months Ended
	Mar. 31, 2020 USD ($) shares	Mar. 31, 2019 USD ($)	Dec. 31, 2019 EUR (€)	Dec. 31, 2019 USD ($) shares	Mar. 31, 2020 USD ($) shares	Dec. 31, 2017 USD ($)	Mar. 31, 2011 USD ($)
Class of Stock [Line Items]
Proceeds from stock options	$ 11,100,000	$ 27,200,000
Treasury stock activity (in shares) | shares	213,352
Treasury stock repurchased	$ 45,100,000
Accrued treasury stock repurchases	$ 5,400,000			$ 0	$ 5,400,000
Shares repurchased (in shares) | shares	10,864			10,651	10,864
Shares repurchased	$ 1,271,500,000			$ 1,226,400,000	$ 1,271,500,000
Accrued dividend RSU	8,600,000				$ 8,600,000
Paid dividend RSU	7,600,000	$ 6,600,000
ATC Europe
Class of Stock [Line Items]
Dividends			€ 24.5	$ 27,000,000.0
2011 Buyback
Class of Stock [Line Items]
Stock repurchase program, authorized amount							$ 1,500,000,000
Treasury stock activity (in shares) | shares					14,310,549
Treasury stock repurchased					$ 1,500,000,000
2017 Buyback
Class of Stock [Line Items]
Stock repurchase program, authorized amount						$ 2,000,000,000.0
Treasury stock repurchased	$ 45,100,000