Summary of Significant Accounting Policies - Income (Loss) Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income (Loss) Per Share-Basic and Diluted
Net Income (Loss)	$ 192,931	$ 68,111	$ 436,496	$ 391,264
Less: Net Income (Loss) Attributable to Noncontrolling Interests	767	428	1,952	2,693
Net Income (Loss) Attributable to Iron Mountain Incorporated (utilized in numerator of Earnings Per Share calculation)	$ 192,164	$ 67,683	$ 434,544	$ 388,571
Weighted-average shares—basic (in shares)	290,937,000	289,762,000	290,673,000	289,255,000
Effect of dilutive potential stock options (in shares)	1,133,952	869,600	1,126,280	522,642
Effect of dilutive potential restricted stock, RSUs and PUs (in shares)	480,919	850,655	494,956	918,954
Weighted-average shares—diluted (in shares)	292,551,871	291,482,255	292,294,236	290,696,596
Basic (in dollars per share)	$ 0.66	$ 0.23	$ 1.49	$ 1.34
Diluted (in dollars per share)	$ 0.66	$ 0.23	$ 1.49	$ 1.34
Antidilutive stock options, RSUs and PUs, excluded from the calculation (in shares)	220,421	351,673	403,362	1,813,880