CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Millions, $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Total Ingersoll Rand Inc. Stockholders' Equity	Total Ingersoll Rand Inc. Stockholders' Equity Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Capital in Excess of Par Value	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjustment	Treasury Stock	Noncontrolling Interests
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201802Member
Balance at beginning of period (shares) at Dec. 31, 2017					198.4
Balance at beginning of period at Dec. 31, 2017	$ 1,476.8	$ 0.0	$ 1,476.8		$ 2.0	$ 2,275.4	$ (577.8)	$ (0.3)	$ (199.8)	$ 0.3	$ (23.0)	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	269.4		269.4				269.4
Issuance of common stock for stock-based compensation plans (shares)					2.7
Issuance of common stock for stock-based compensation plans	6.8		6.8			6.8
Purchases of treasury stock	(11.5)		(11.5)								(11.5)
Share repurchase program	(29.2)		(29.2)								(29.2)
Issuance of treasury stock for stock-based compensation plans	0.3		0.3			(10.4)					10.7
Stock-based compensation	10.9		10.9			10.9
Other comprehensive income (loss), net of tax	(47.5)		(47.5)						(47.5)
Balance at end of period (shares) at Dec. 31, 2018					201.1
Balance at end of period at Dec. 31, 2018	$ 1,676.0	0.0	1,676.0		$ 2.0	2,282.7	(308.7)	8.2	(247.0)	$ (8.2)	(53.0)	0.0
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 159.1		159.1				159.1
Issuance of common stock for stock-based compensation plans (shares)					5.7
Issuance of common stock for stock-based compensation plans	34.6		34.6		$ 0.1	34.5
Purchases of treasury stock	(18.6)		(18.6)								(18.6)
Issuance of treasury stock for stock-based compensation plans	8.4		8.4			(26.4)					34.8
Stock-based compensation	11.2		11.2			11.2
Other comprehensive income (loss), net of tax	(0.8)		(0.8)						(0.8)
Balance at end of period (shares) at Dec. 31, 2019					206.8
Balance at end of period at Dec. 31, 2019	1,869.9	$ (1.0)	1,869.9	$ (1.0)	$ 2.1	2,302.0	(141.4)	$ (1.0)	(256.0)		(36.8)	0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(32.4)		(33.3)				(33.3)					0.9
Acquisition of Ingersoll Rand Industrial (Note 3) (shares)					211.0
Acquisition of Ingersoll Rand Industrial (Note 3)	7,010.3		6,937.0		$ 2.1	6,934.9						73.3
Costs of issuing equity securities (Note 3)	(1.0)		(1.0)			(1.0)
Issuance of common stock for stock-based compensation plans (shares)					2.3
Issuance of common stock for stock-based compensation plans	20.1		20.1			20.1
Purchases of treasury stock	(2.1)		(2.1)								(2.1)
Issuance of treasury stock for stock-based compensation plans	2.4		2.4			(3.2)					5.6
Stock-based compensation	57.5		57.5			57.5
Other comprehensive income (loss), net of tax	268.8		270.2						270.2			(1.4)
Adjustments for shares tendered in open offer (Note 12)	(14.9)											(14.9)
Adjustments for shares sold in offer for sale (Note 12)	11.9											11.9
Balance at end of period (shares) at Dec. 31, 2020					420.1
Balance at end of period at Dec. 31, 2020	$ 9,189.5		$ 9,119.7		$ 4.2	$ 9,310.3	$ (175.7)		$ 14.2		$ (33.3)	$ 69.8