Summary of Significant Accounting Policies - Income (Loss) Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income (Loss) Per Share-Basic and Diluted
Net Income (Loss)	$ 1,143	$ 201,858	$ 66,678	$ 243,565
Less: Net Income (Loss) Attributable to Noncontrolling Interests	1,029	1,777	1,969	1,185
Net Income (Loss) Attributable to Iron Mountain Incorporated (utilized in numerator of Earnings Per Share calculation)	$ 114	$ 200,081	$ 64,709	$ 242,380
Weighted-average shares—basic (in shares)	291,825,000	290,756,000	291,633,000	290,542,000
Effect of dilutive potential stock options (in shares)	1,322,000	1,249,262	1,269,000	1,122,444
Effect of dilutive potential restricted stock, RSUs and PUs (in shares)	380,000	481,972	386,000	501,975
Weighted-average shares—diluted (in shares)	293,527,000	292,487,234	293,288,000	292,166,419
Basic (in dollars per share)	$ 0.00	$ 0.69	$ 0.22	$ 0.83
Diluted (in dollars per share)	$ 0.00	$ 0.68	$ 0.22	$ 0.83
Antidilutive stock options, RSUs and PUs, excluded from the calculation (in shares)	157,132	234,085	151,431	494,833