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obligation relates to plans that are not funded Percent Of Our Projected Benefit Obligation Relates To Plans That Are Not Funded Percent Of Our Projected Benefit Obligation Relates To Plans That Are Not Funded Corporate and Non-U.S. Bonds Corporate and Non-U.S. Bonds [Member] Corporate And Non U S Bonds [Member] Prior service costs and net actuarial gains (losses), net Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax Repurchase of ordinary shares Treasury Stock, Shares, Acquired Share Repurchase Authorization [Member] Share Repurchase Authorization [Member] Share Repurchase Authorization Weighted average exercise price, Exercised, in dollars per share Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Award Timing Disclosures [Line Items] Schedule of Inventory Schedule of Inventory, Current [Table Text Block] Service cost Service cost Defined Benefit Plan, Service Cost Shareholders' Equity Equity [Text Block] Net earnings attributable to Allegion plc Net Income (Loss) Attributable to Parent Subsequent Event [Table] Subsequent Event [Table] Construction in progress Construction in Progress [Member] Other accrued liabilities, current Other Accrued Liabilities, Current Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Projected pension expense Projected pension expense Projected amount of pension benefit costs expected to be recognized during the next fiscal year for (1) defined benefit plans and (2) defined contribution plans. For defined benefit plans, pension expense includes the following components: service cost, interest cost, expected return on plan assets, gain (loss) on plan assets, prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments. For defined contribution plans, the pension expense generally equals the firm's contribution to employees' accounts (if the firm contributes) during the period. Other adjustments Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Deductions SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction Preferred shares authorized Preferred Stock, Shares Authorized Repurchase of ordinary shares Repurchase of ordinary shares Payments for Repurchase of Common Stock Adoption Date Trading Arrangement Adoption Date Mechanical products Mechanical Products [Member] Mechanical Products [Member] Customer Relationships [Member] Customer Relationships [Member] Operating income Operating income (loss) Operating Income (Loss) Line of Credit Line of Credit [Member] Retained earnings Retained Earnings (Accumulated Deficit) Lessee, Operating Lease Asset and Liability, Other Information Assets and Liabilities, Lessee [Table Text Block] Assets and Liabilities, Lessee Schedule of compensation expense by plan Share-Based Payment Arrangement, Cost by Plan [Table Text Block] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Curtailments and settlements Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment Class of Stock [Axis] Class of Stock [Axis] Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Other Deferred Tax Liabilities, Other Retirement Plan Type [Axis] Retirement Plan Type [Axis] Statement [Table] Statement [Table] Other income, net Other (income) expense, net Other Nonoperating Income (Expense) Actual return on plan assets Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) Deferred tax benefit: Deferred Income Tax Expense (Benefit) Adjustments to arrive at net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Reductions related to lapses of statute of limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Cash flows from financing activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net, Total Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill Foreign Tax Jurisdiction, Other Foreign Tax Jurisdiction, Other [Member] Contract with Customer, Liability Contract with Customer, Liability Variable Rate [Domain] Variable Rate [Domain] All Adjustments to Compensation All Adjustments to Compensation [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Amendment Flag Amendment Flag Tax benefit Share-Based Payment Arrangement, Expense, Tax Benefit Total number of shares authorized by the shareholders Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Schedule of Pension Plan Assets Schedule of Allocation of Plan Assets [Table Text Block] Termination Date Trading Arrangement Termination Date Currency translation and other Valuation Allowances And Reserves Currency Translation Valuation Allowances And Reserves Currency Translation Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Stock option activity Share-Based Payment Arrangement, Option, Activity [Table Text Block] Unrecognized tax benefits, income tax penalties and interest accrued Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Business Combination, Acquiree's Revenue since Acquisition Date, Actual Business Combination, Acquiree's Revenue since Acquisition Date, Actual Weighted-average number of basic shares Weighted Average Number of Shares Outstanding, Basic Unrecognized Tax Benefits that Would Impact Effective Tax Rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Weighted-Average Shares Outstanding for EPS Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Shares subject to options, Exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Domain] Exercise Price Range [Domain] Subsequent Events [Abstract] Subsequent Events [Abstract] Segment Reporting [Abstract] Segment Reporting [Abstract] Interest and penalties, net of tax, related to uncertain tax positions Income Tax Examination, Penalties and Interest Expense Total rental expense Operating Lease, Expense Interest rate Long-Term Debt, Percentage Bearing Variable Interest, Percentage Rate Debt Disclosure [Abstract] Debt Disclosure [Abstract] Cash dividends declared Dividends, Cash Inventory, Net [Abstract] Inventory, Net [Abstract] Cash paid for interest Interest Paid, Including Capitalized Interest, Operating and Investing Activities Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Ordinary shares, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Current tax receivable Income Taxes Receivable, Current 2031 - 2035 Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years Shares subject to options, Granted Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Use of Estimates Use of Estimates, Policy [Policy Text Block] Number of options outstanding, in shares Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Subsequent Events Subsequent Events [Text Block] Currency translation Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Insider Trading Arrangements [Line Items] Weighted average exercise price, Cancelled, in dollars per share Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Decrease to valuation allowance Decrease to valuation allowance [Member] Decrease to valuation allowance [Member] Raw materials Inventory, Raw Materials, Gross Total liabilities Liabilities Term Loan Term Loan [Member] Term Loan Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Additions based on tax positions related to the current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Business Combination, Intangible Asset, Acquired, Finite-Lived and Indefinite-Lived Business Combination, Intangible Asset, Acquired, Finite-Lived and Indefinite-Lived [Table Text Block] Consolidation Items [Axis] Consolidation Items [Axis] Variable Rate [Axis] Variable Rate [Axis] Restricted stock units activity Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] alle_LeaseArrangementTypeAxis [Axis] alle_LeaseArrangementTypeAxis [Axis] alle_LeaseArrangementTypeAxis