Summary of Significant Accounting Policies - Income Per Share, Allowance for Doubful Accounts, Income Taxes, and Concentration of Credit Risk (Details) (USD $)
3 Months Ended
Mar. 31, 2015
bank
fund
Mar. 31, 2014
Dec. 31, 2014
fund
bank
Income (Loss) Per Share-Basic and Diluted      
Income (loss) from continuing operations $ 41,739,000 $ 42,721,000  
Total (loss) income from discontinued operations 0 (612,000)  
Net income (loss) attributable to Iron Mountain Incorporated 41,096,000 41,667,000  
Weighted-average shares—basic 210,237,000 191,879,000  
Effect of dilutive potential stock options (in shares) 1,223,330 682,801  
Effect of dilutive potential restricted stock, RSUs and PUs (in shares) 788,758 507,219  
Weighted-average shares—diluted 212,249,088 193,069,020  
Earnings (Losses) per share-basic:      
Income (Loss) from continuing operations (in dollars per share) $ 0.20 $ 0.22  
Total (loss) income income discontinued operations (see Note 9) (in dollars per share) $ 0.00 $ 0.00  
Net Income (Loss) Attributable to Iron Mountain Incorporated (in dollars per share) $ 0.20 $ 0.22  
Earnings (Losses) per share-diluted:      
Income (Loss) from continuing operations (in dollars per share) $ 0.20 $ 0.22  
Total (loss) income from discontinued operations (see Note 9) (in dollars per share) $ 0.00 $ 0.00  
Net Income (Loss) Attributable to Iron Mountain Incorporated (in dollars per share) $ 0.19 $ 0.22  
Antidilutive stock options, RSUs and PUs, excluded from the calculation (in shares) 358,233 1,380,962  
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 942,000 966,000  
Accrued interest and penalties recorded 6,167,000   5,884,000
Effective tax rates (as a percent) 27.60% 45.80%  
Federal statutory tax rate (as a percent)   35.00%  
Effective tax rate increase (decrease) (as a percent)   1.10%  
FX impact on increase (decrease) in effective income tax rate (as a percent)   1.30%  
Concentrations of Credit Risk      
Number of global banks with cash, cash equivalent and restricted cash held on deposit 3   3
Number of "Triple A" rated money market funds with cash, cash equivalent and restricted cash held on deposit 1   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 139,605,000   159,793,000
Money market funds and time deposits $ 33,909,000   $ 53,032,000