Quarterly Results of Operations (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 1,079,590,000	$ 1,062,224,000	$ 1,066,907,000	$ 1,053,863,000					$ 4,262,584,000
Total revenues					$ 1,061,489,000	$ 1,060,991,000	$ 1,060,823,000	$ 1,042,458,000		$ 4,225,761,000	$ 3,845,578,000
Operating income (loss)	206,074,000	223,474,000	193,115,000	158,675,000	254,053,000	195,635,000	201,460,000	157,119,000	781,338,000	808,267,000	634,051,000
Income (loss) from continuing operations	37,104,000	108,284,000	92,347,000	30,476,000	158,557,000	77,349,000	92,263,000	39,389,000	268,211,000	367,558,000	178,015,000
Total (loss) income from discontinued operations	0	0	128,000	(24,000)	0	(11,605,000)	(360,000)	(462,000)	104,000	(12,427,000)	(6,291,000)
Net Income (Loss)	37,104,000	108,284,000	92,475,000	30,452,000	158,557,000	65,744,000	91,903,000	38,927,000	268,315,000	355,131,000	171,724,000
Net income (loss) attributable to Iron Mountain Incorporated	$ 37,700,000	$ 107,675,000	$ 92,441,000	$ 29,561,000	$ 157,844,000	$ 65,869,000	$ 91,761,000	$ 38,459,000	$ 267,377,000	$ 353,933,000	$ 170,113,000
Earnings (Losses) per Share—Basic:
Income (loss) per share from continuing operations (in dollars per share)	$ 0.13	$ 0.37	$ 0.32	$ 0.10	$ 0.55	$ 0.27	$ 0.32	$ 0.14	$ 0.93	$ 1.28	$ 0.66
Total (loss) income per share from discontinued operations (in dollars per share)	0	0	0	0	0	(0.04)	0	0	0	(0.04)	(0.02)
Net income (loss) per share attributable to Iron Mountain Incorporated (in dollars per share)	0.13	0.37	0.32	0.10	0.55	0.23	0.32	0.13	0.93	1.24	0.64
Earnings (Losses) per Share—Diluted:
Income (loss) per share from continuing operations (in dollars per share)	0.13	0.37	0.32	0.10	0.55	0.27	0.32	0.14	0.93	1.28	0.66
Total (loss) income per share from discontinued operations (in dollars per share)	0	0	0	0	0	(0.04)	0	0	0	(0.04)	(0.02)
Net income (loss) per share attributable to Iron Mountain Incorporated (in dollars per share)	$ 0.13	$ 0.37	$ 0.32	$ 0.10	$ 0.55	$ 0.23	$ 0.32	$ 0.13	$ 0.93	$ 1.23	$ 0.64
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Increase in gains (losses) on foreign currency transactions	$ (63,000,000)				$ 20,000,000
Restructuring Charges	48,600,000								$ 48,597,000	$ 0	$ 0
(Gain) Loss on disposal/write-down of property, plant and equipment, net	37,500,000
Decrease in tax provision	$ 5,100,000				11,200,000
Initial United States Divestments | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Charge related to resolution of post-closing adjustment to Access Contingent Consideration					11,100,000
United Kingdom
Quarterly Financial Information Disclosure [Abstract]
Total revenues									$ 274,931,000
Total revenues										$ 280,993,000	$ 246,373,000
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Gain) Loss on disposal/write-down of property, plant and equipment, net					62,500,000
Income (Loss) From Continuing Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Immaterial misstatement					$ 274,000	$ 1,279,000	$ 1,640,000	$ 6,225,000