Equity Compensation - Narrative (Details) $ / shares in Units, $ in Millions					3 Months Ended	12 Months Ended			121 Months Ended
	May 11, 2021 USD ($)	Mar. 31, 2021 USD ($) shares	Nov. 23, 2020 USD ($) shares	Mar. 12, 2015 shares	Jan. 31, 2021 USD ($) shares	Jan. 31, 2022 USD ($) period Plan trading_day $ / shares shares	Jan. 31, 2021 USD ($) $ / shares shares	Jan. 31, 2020 USD ($) $ / shares	Jan. 31, 2022 USD ($) shares
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Number of active stock plans | Plan						4
Number of additional share authorized (in shares)									36,100,000
Shares available for future issuance (in shares)						13,300,000			13,300,000
Liability classified awards, settled | $						$ 2.7	$ 28.7	$ 23.5
Market capitalization level of peer group | $						2,000.0			$ 2,000.0
Fair value of common stock issued related to business combination | $						$ 6.1	37.9	0.0
Consecutive trading days | trading_day						90
Stock-based compensation expense related to stock awards and Employee Qualified Stock Purchase Plan ("ESPP") purchases | $						$ 558.5	399.8	362.4
Number of exercise period | period						4
Term of exercise period						6 months
Term of offering period						24 months
Spacemaker
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period			3 years
Fair value of common stock issued related to business combination | $			$ 37.9
Shares issued in period (in shares)			73,632
Business acquisition, equity interest issued or issuable, number of shares (in shares)			147,264
Stock-based compensation expense related to stock awards and Employee Qualified Stock Purchase Plan ("ESPP") purchases | $					$ 2.0
Innovyze
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Fair value of common stock issued related to business combination | $		$ 2.6
Business acquisition, equity interest issued or issuable, number of shares (in shares)		9,277
Upchain
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Fair value of common stock issued related to business combination | $	$ 13.1					$ 13.1
Business acquisition, equity interest issued or issuable, number of shares (in shares)						48,000
Stock-based compensation expense related to stock awards and Employee Qualified Stock Purchase Plan ("ESPP") purchases | $						$ 3.1
Upchain | Year One
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting percentage (up to percentage)	40.00%
Upchain | Year Two
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting percentage (up to percentage)	60.00%
Other
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Fair value of common stock issued related to business combination | $						$ 10.6
Business acquisition, equity interest issued or issuable, number of shares (in shares)						39,000
Common Stock
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Liability classified awards, settled | $						$ 2.7	28.7	23.5
Restricted Stock Units (RSUs)
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Restricted stock granted (in shares)						2,000,000
Share based compensation expense, restricted stock units | $						$ 425.1	$ 308.9	$ 274.5
Total compensation cost related to non-vested awards not yet recognized | $						$ 672.8			$ 672.8
Total compensation cost related to non-vested awards not yet recognized, weighted average period of recognition						1 year 7 months 6 days
Number of awards granted but unreleased						3,600,000			3,600,000
Restricted Stock Units (RSUs) | Maximum
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period						3 years
Restricted Stock Units (RSUs) and Performance Stock Units (PSUs)
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Granted (in dollars per share) | $ / shares						$ 288.13	$ 224.20	$ 156.24
Fair value of units vested in period | $						$ 619.8	$ 503.4	$ 361.0
Restricted stock granted (in shares)						2,294,100
Number of awards granted but unreleased					4,503,900	4,032,700	4,503,900		4,032,700
Performance Stock Unit
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period						3 years
Restricted stock granted (in shares)						200,000
Share based compensation expense, restricted stock units | $						$ 68.2	$ 30.7	27.1
Total compensation cost related to non-vested awards not yet recognized | $						$ 10.4			$ 10.4
Total compensation cost related to non-vested awards not yet recognized, weighted average period of recognition						7 months 6 days
Number of awards granted but unreleased						400,000			400,000
Performance Stock Unit | Year One
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting percentage (up to percentage)						33.33%
Performance Stock Unit | Year Two
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting percentage (up to percentage)						33.33%
Performance Stock Unit | Year Three
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting percentage (up to percentage)						33.33%
Performance Stock Unit | Management
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period						1 year
Restricted stock granted (in shares)						100,000
Common Stock
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Shares of common stock reserved for issuance (in shares)						9,000			9,000
Shares issued in period (in shares)						8,300
Value of shares issued | $						$ 2.7
Stock-based compensation expense related to stock awards and Employee Qualified Stock Purchase Plan ("ESPP") purchases | $						$ 16.5	2.4
Common Stock | Spacemaker
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Fair value of common stock issued related to business combination | $							$ 4.9
Restricted Stock
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period						2 years
Restricted Stock | Spacemaker
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period							3 years
Shares issued in period (in shares)							73,632
Restricted Stock | Innovyze
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Shares issued in period (in shares)		9,277					9,277
Restricted Stock | Other
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Fair value of common stock issued related to business combination | $						$ 3.5
Shares issued in period (in shares)						12,782
Employee Stock Plan 2012
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Shares of common stock reserved for issuance (in shares)						57,300,000			57,300,000
Restricted stock award, net of forfeitures (in shares)						51,300,000
Shares forfeited (in shares)						6,000,000
Shares granted to shares issued (in shares)						1.79
Shares available for future issuance (in shares)						6,900,000			6,900,000
Employee Stock Plan 2012 | Stock Options and Restricted Stock
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Grants in period, net of forfeitures (in shares)						59,100,000
Share based payment award options expiration term (in years)						10 years
Vesting period						3 years
Directors stock plan 2012
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Shares of common stock reserved for issuance (in shares)						1,700,000			1,700,000
Shares granted to shares issued (in shares)						2.11
Shares available for future issuance (in shares)						700,000			700,000
Reduction of shares reserved for issuance (in shares)				900,000
Directors stock plan 2012 | Restricted Stock Units (RSUs)
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Grants in period, net of forfeitures (in shares)						1,000,000
2012 Outside Directors' Plan | Minimum
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period						1 year
2012 Outside Directors' Plan | Maximum
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period						3 years
PlanGrid 2012 Plan
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Share based payment award options expiration term (in years)						10 years
Vesting period						4 years
Options outstanding (in shares)						67,000			67,000
BuildingConnected 2012 Plan
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Share based payment award options expiration term (in years)						10 years
Vesting period						4 years
Options outstanding (in shares)						14,000			14,000
ESP Plan
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Shares available for future issuance (in shares)						5,600,000			5,600,000
Percentage of compensation that eligible employees can use to purchase common stock, maximum						15.00%
Percentage of fair market value eligible employees can purchase common stock, minimum						85.00%
Number of exercise period | period						4
Term of exercise period						6 months
Term of offering period						24 months
Employee service share based compensation recognized compensation costs on nonvested restricted shares | $						$ 37.1	$ 40.1	$ 33.3