Guarantor Financial Information (Condensed Consolidating Statement of Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net revenues	$ 2,118.3	$ 2,069.6	$ 2,023.3
Cost of goods sold	(1,264.6)	(1,208.1)	(1,197.7)
Selling and administrative expenses	(527.4)	(483.1)	(454.3)
Gain (loss) on sale/asset impairment	0	(137.6)	0
Operating Income (Loss)	326.3	240.8	371.3
Equity earnings (loss) in affiliates, net of tax	0	0	0
Interest Expense	53.8	10.2	1.5
Intercompany Interest And Fees	0	0	0
Other, net	4.6	7.2	3.1
Earnings (loss) before income taxes	267.9	223.4	366.7
Benefit (provision) for income taxes	(84.2)	(175.0)	(136.7)
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	183.7	48.4	230.0
Discontinued operations, net of tax	(11.1)	(3.6)	(4.2)
Net earnings	172.6	44.8	225.8
Less: Net earnings attributable to noncontrolling interests	2.6	(12.5)	(5.7)
Net earnings (loss) attributable to Allegion plc	175.2	32.3	220.1
Total comprehensive income (loss), net of tax	120.4	(43.4)	247.7
Total comprehensive (income) loss attributable to noncontrolling interests	3.3	(13.3)	(6.2)
Total comprehensive income (loss) attributable to Allegion plc	123.7	(56.7)	241.5
Goodwill, Impairment Loss	0	137.6	0
Parent Company [Member]
Net revenues	0	0	0
Cost of goods sold	0	0	0
Selling and administrative expenses	(4.5)	(0.9)	0
Operating Income (Loss)	(4.5)	(0.9)	0
Equity earnings (loss) in affiliates, net of tax	182.0	33.2	220.1
Interest Expense	5.6	0	0
Intercompany Interest And Fees	3.2	0	0
Other, net	0.1	0	0
Earnings (loss) before income taxes	175.2	32.3	220.1
Benefit (provision) for income taxes	0	0	0
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	175.2	32.3	220.1
Discontinued operations, net of tax	0	0	0
Net earnings	175.2	32.3	220.1
Less: Net earnings attributable to noncontrolling interests	0	0	0
Net earnings (loss) attributable to Allegion plc	175.2	32.3	220.1
Total comprehensive income (loss), net of tax	123.7	(56.7)	241.5
Total comprehensive (income) loss attributable to noncontrolling interests	0	0	0
Total comprehensive income (loss) attributable to Allegion plc	123.7	(56.7)	241.5
Goodwill, Impairment Loss	0	0	0
Other Subsidiaries [Member]
Net revenues	916.4	880.0	967.3
Cost of goods sold	(659.5)	(613.4)	(701.1)
Selling and administrative expenses	(218.3)	(242.8)	(197.5)
Operating Income (Loss)	38.6	(113.8)	68.7
Equity earnings (loss) in affiliates, net of tax	351.5	233.6	198.8
Interest Expense	1.0	1.8	1.5
Intercompany Interest And Fees	(225.7)	(16.4)	0
Other, net	(4.9)	9.4	(14.2)
Earnings (loss) before income taxes	158.5	111.0	251.8
Benefit (provision) for income taxes	95.7	(53.3)	(20.4)
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	254.2	57.7	231.4
Discontinued operations, net of tax	(11.1)	(3.6)	(5.7)
Net earnings	243.1	54.1	225.7
Less: Net earnings attributable to noncontrolling interests	2.6	(12.5)	(5.7)
Net earnings (loss) attributable to Allegion plc	245.7	41.6	220.0
Total comprehensive income (loss), net of tax	242.4	55.0	226.2
Total comprehensive (income) loss attributable to noncontrolling interests	3.3	(13.3)	(6.2)
Total comprehensive income (loss) attributable to Allegion plc	245.7	41.7	220.0
Goodwill, Impairment Loss	0	137.6	0
Consolidating Adjustments [Member]
Net revenues	(198.0)	(205.4)	(242.0)
Cost of goods sold	198.0	205.4	242.0
Selling and administrative expenses	0	0	0
Operating Income (Loss)	0	0	0
Equity earnings (loss) in affiliates, net of tax	(711.2)	(368.7)	(623.4)
Interest Expense	(10.8)	0	0
Intercompany Interest And Fees	0	0	0
Other, net	0	0	0
Earnings (loss) before income taxes	(700.4)	(368.7)	(623.4)
Benefit (provision) for income taxes	(4.0)	0	0
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	(704.4)	(368.7)	(623.4)
Discontinued operations, net of tax	0	0	0
Net earnings	(704.4)	(368.7)	(623.4)
Less: Net earnings attributable to noncontrolling interests	0	0	0
Net earnings (loss) attributable to Allegion plc	(704.4)	(368.7)	(623.4)
Total comprehensive income (loss), net of tax	(704.4)	(368.7)	(623.4)
Total comprehensive (income) loss attributable to noncontrolling interests	0	0	0
Total comprehensive income (loss) attributable to Allegion plc	(704.4)	(368.7)	(623.4)
Goodwill, Impairment Loss	0	0	0
Subsidiary Issuer [Member]
Net revenues	0	0	0
Cost of goods sold	0	0	0
Selling and administrative expenses	(0.2)	0	0
Operating Income (Loss)	(0.2)	0	0
Equity earnings (loss) in affiliates, net of tax	170.8	95.2	203.0
Interest Expense	58.0	8.4	0
Intercompany Interest And Fees	(63.0)	(4.6)	0
Other, net	0	0	0
Earnings (loss) before income taxes	49.6	82.2	203.0
Benefit (provision) for income taxes	46.7	4.6	0
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	96.3	86.8	203.0
Discontinued operations, net of tax	0	0	0
Net earnings	96.3	86.8	203.0
Less: Net earnings attributable to noncontrolling interests	0	0	0
Net earnings (loss) attributable to Allegion plc	96.3	86.8	203.0
Total comprehensive income (loss), net of tax	96.3	86.8	203.0
Total comprehensive (income) loss attributable to noncontrolling interests	0	0	0
Total comprehensive income (loss) attributable to Allegion plc	96.3	86.8	203.0
Goodwill, Impairment Loss	0	0	0
Guarantor Subsidiaries [Member]
Net revenues	1,399.9	1,395.0	1,298.0
Cost of goods sold	(803.1)	(800.1)	(738.6)
Selling and administrative expenses	(304.4)	(239.4)	(256.8)
Operating Income (Loss)	292.4	355.5	302.6
Equity earnings (loss) in affiliates, net of tax	6.9	6.7	1.5
Interest Expense	0	0	0
Intercompany Interest And Fees	285.5	21.0	0
Other, net	0.2	(16.6)	11.1
Earnings (loss) before income taxes	585.0	366.6	315.2
Benefit (provision) for income taxes	(222.6)	(126.3)	(116.3)
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	362.4	240.3	198.9
Discontinued operations, net of tax	0	0	1.5
Net earnings	362.4	240.3	200.4
Less: Net earnings attributable to noncontrolling interests	0	0	0
Net earnings (loss) attributable to Allegion plc	362.4	240.3	200.4
Total comprehensive income (loss), net of tax	362.4	240.3	200.4
Total comprehensive (income) loss attributable to noncontrolling interests	0	0	0
Total comprehensive income (loss) attributable to Allegion plc	362.4	240.3	200.4
Goodwill, Impairment Loss	$ 0	$ 0	$ 0