SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income [Abstract]
Net earnings, basic	$ 157.9	$ 318.8	$ 233.8	$ 173.2	$ 687.8	$ 171.5	$ 184.8	$ 183.0	$ 883.7	$ 1,227.1	$ 711.8
Net earnings, diluted									$ 883.7	$ 1,227.1	$ 711.8
Shares [Abstract]
Outstanding shares, basic (in shares)									101.4	102.4	102.5
Dilutive effect of stock options (in shares)									1.2	1.4	1.5
Dilutive effect of convertible debt, net of tax (in shares)									0.0	0.1	0.3
Outstanding shares, diluted (in shares)									102.6	103.9	104.3
Per Share Amount [Abstract]
Earnings Per Share, Basic	$ 1.58	$ 3.14	$ 2.29	$ 1.70	$ 6.73	$ 1.68	$ 1.80	$ 1.79	$ 8.71	$ 11.99	$ 6.94
Diluted earnings per share (in dollars per share)	$ 1.56	$ 3.10	$ 2.27	$ 1.67	$ 6.63	$ 1.65	$ 1.78	$ 1.75	$ 8.61	$ 11.81	$ 6.82