Summary of Significant Accounting Policies - Income Per Share, Allowance for Doubful Accounts, Income Taxes, and Concentration of Credit Risk (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($) bank fund $ / shares shares	Sep. 30, 2014 USD ($) $ / shares shares	Sep. 30, 2015 USD ($) bank fund $ / shares shares	Sep. 30, 2014 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) bank fund
Income (Loss) Per Share-Basic and Diluted
Income (loss) from continuing operations	$ 23,517,000	$ 858,000	$ 119,263,000	$ 316,281,000
Total (loss) income from discontinued operations	0	0	0	(938,000)
Net income (loss) attributable to Iron Mountain Incorporated	$ 23,110,000	$ 66,000	$ 117,536,000	$ 313,370,000
Weighted-average shares—basic | shares	210,912,000	193,360,000	210,616,000	192,540,000
Effect of dilutive potential stock options (in shares) | shares	621,615	1,023,890	934,553	823,036
Effect of dilutive potential restricted stock, RSUs and PUs (in shares) | shares	382,995	520,644	530,252	470,060
Weighted-average shares—diluted | shares	211,917,000	194,905,000	212,081,000	193,833,000
Earnings (Losses) per share-basic:
Income (Loss) from continuing operations (in dollars per share) | $ / shares	$ 0.11	$ 0.00	$ 0.57	$ 1.64
Total (loss) income income discontinued operations (see Note 9) (in dollars per share) | $ / shares	0.00	0.00	0.00	0.00
Net Income (Loss) Attributable to Iron Mountain Incorporated (in dollars per share) | $ / shares	0.11	0.00	0.56	1.63
Earnings (Losses) per share-diluted:
Income (Loss) from continuing operations (in dollars per share) | $ / shares	0.11	0.00	0.56	1.63
Total (loss) income from discontinued operations (see Note 9) (in dollars per share) | $ / shares	0.00	0.00	0.00	0.00
Net Income (Loss) Attributable to Iron Mountain Incorporated (in dollars per share) | $ / shares	$ 0.11	$ 0.00	$ 0.55	$ 1.62
Antidilutive stock options, RSUs and PUs, excluded from the calculation (in shares) | shares	2,262,827	609,385	1,318,811	1,149,441
Allowance for Doubtful Accounts and Credit Memo Reserves
The general period to charge-off uncollectible balances of receivable, as circumstances warrant, is no later than this period of time past due			1 year
Income Taxes:
Period of time subject to a separate corporate income tax			10 years
Increase (decrease) in gross interest and penalties recorded	$ 180,000	$ 246,000	$ 1,759,000	$ 581,000
Accrued interest and penalties recorded	$ 6,595,000		$ 6,595,000		$ 5,884,000
Tax benefit from reevaluation of deferred tax assets				212,151,000
Effective tax rates (as a percent)	14.30%		18.60%
Federal statutory tax rate (as a percent)		35.00%
Increase in provision related to federal, state and foreign taxes no longer considered permanently invested		$ 13,226,000		49,310,000
Increase in tax provision related to amended tax returns		26,390,000
Income Tax Reconciliation Adjustments Related to REIT		$ 7,993,000		$ 41,828,000
Tax benefit resulting from lapse in statute of limitations	$ 4,100,000
Tax benefit from change in taxation status	$ 9,000,000
Concentrations of Credit Risk
Number of global banks with cash, cash equivalent and restricted cash held on deposit | bank	8		8		3
Number of "Triple A" rated money market funds with cash, cash equivalent and restricted cash held on deposit | fund	2		2		2
Maximum investment limit in any one mutual fund			$ 50,000,000
Maximum investment limit in any one financial institution			75,000,000
Cash, cash equivalent and restricted cash	$ 492,899,000		492,899,000		$ 159,793,000
Money market funds and time deposits	$ 379,056,000		$ 379,056,000		$ 53,032,000