Financial Instruments - Schedule of Cost and Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Apr. 30, 2026	Jan. 31, 2026
Other investments
Investments	$ 2,559.0	$ 2,261.0
Total, Gross unrealized gains	0.0	21.0
Total, Gross unrealized losses	(1.0)	0.0
Investments, Fair Value Disclosure	2,558.0	2,282.0
Rabbi Trust
Other investments
Deferred compensation liability, current	14.0	14.0
Deferred compensation liability, non-current	131.0	123.0
Deferred compensation liability	146.0	137.0
Mutual funds
Other investments
Other investments	145.0	117.0
Other investments, gross unrealized gains	0.0	20.0
Other investments, gross unrealized losses	0.0	0.0
Other investments, fair value	145.0	137.0
Cash equivalents | Money market funds
Marketable securities:
Amortized Cost	1,349.0	1,107.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	1,349.0	1,107.0
Cash equivalents | Commercial paper
Marketable securities:
Amortized Cost	213.0	163.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	213.0	163.0
Cash equivalents | Certificates of deposit
Marketable securities:
Amortized Cost	73.0	54.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	73.0	54.0
Cash equivalents | U.S. government securities
Marketable securities:
Amortized Cost	138.0	96.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	138.0	96.0
Cash equivalents | Agency securities
Marketable securities:
Amortized Cost	2.0
Gross Unrealized Gains	0.0
Gross Unrealized Losses	0.0
Fair Value	2.0
Cash equivalents | Other
Marketable securities:
Amortized Cost		1.0
Gross Unrealized Gains		0.0
Gross Unrealized Losses		0.0
Fair Value		1.0
Marketable securities, short-term | Commercial paper
Marketable securities:
Amortized Cost	112.0	155.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	112.0	155.0
Marketable securities, short-term | Certificates of deposit
Marketable securities:
Amortized Cost	5.0	16.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	5.0	16.0
Marketable securities, short-term | U.S. government securities
Marketable securities:
Amortized Cost	13.0	67.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	13.0	67.0
Marketable securities, short-term | Corporate debt securities
Marketable securities:
Amortized Cost	82.0	66.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	82.0	66.0
Marketable securities, short-term | Asset-backed securities
Marketable securities:
Amortized Cost	29.0	25.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	29.0	25.0
Marketable securities, short-term | Other
Marketable securities:
Amortized Cost	12.0	19.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	12.0	19.0
Marketable securities, long-term | U.S. government securities
Marketable securities:
Amortized Cost	97.0	83.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	(1.0)	0.0
Fair Value	96.0	83.0
Marketable securities, long-term | Agency securities
Marketable securities:
Amortized Cost	11.0
Gross Unrealized Gains	0.0
Gross Unrealized Losses	0.0
Fair Value	11.0
Marketable securities, long-term | Corporate debt securities
Marketable securities:
Amortized Cost	164.0	156.0
Gross Unrealized Gains	0.0	1.0
Gross Unrealized Losses	0.0	0.0
Fair Value	164.0	157.0
Marketable securities, long-term | Asset-backed securities
Marketable securities:
Amortized Cost	81.0	85.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	81.0	85.0
Marketable securities, long-term | Agency mortgage-backed securities
Marketable securities:
Amortized Cost	23.0	23.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	23.0	23.0
Marketable securities, long-term | Other
Marketable securities:
Amortized Cost	10.0	28.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	$ 10.0	$ 28.0