Selected Quarterly Financial Data (Unaudited), Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income tax expense (benefit)									$ 691.7	$ 308.5	$ 280.5
Net income	$ (100.4)	$ 280.3	$ 253.6	$ 227.3	$ 238.3	$ 227.1	$ 208.7	$ 158.4	660.7	832.6	772.3
Net income attributable to Amphenol Corporation shareholders	$ (103.4)	$ 277.5	$ 251.5	$ 224.9	$ 235.4	$ 224.3	$ 206.5	$ 156.6	$ 650.5	$ 822.9	$ 763.5
Net income (loss) per common share—Diluted (in dollars per share)	$ (0.34)	$ 0.88	$ 0.80	$ 0.71	$ 0.75	$ 0.71	$ 0.65	$ 0.50	$ 2.06	$ 2.61	$ 2.41
Operating income	$ 399.4	$ 377.9	$ 336.2	$ 314.1	$ 339.1	$ 326.3	$ 300.3	$ 239.4	$ 1,427.6	$ 1,205.2	$ 1,104.7
Acquisition-related expenses			4.0						$ 4.0	$ 36.6	$ 5.7
Acquisition-related expenses, net of tax			3.7
Provisional Tax Act Charge	$ 398.5
Impact on earnings per share related to Tax Cuts and Jobs Act (in dollars per share)	$ (1.26)
Anti-dilutive stock options, excluded from the computations of earning per share (in shares)	12.4								1.6	8.5	6.3
Earnings per share - diluted change (in dollars per share)	$ 0.01
Operating income (loss), aggregate effect			(4.0)
Net income, aggregate effect	$ (377.7)		17.5
Net income attributable to Amphenol Corporation shareholders, aggregate effect	$ (377.7)		$ 17.5
Earnings per share - diluted, aggregate effect (in dollars per share)	$ (1.20)		$ 0.06
FCI Asia Pte Ltd (“FCI”)
Acquisition-related expenses								30.3
Acquisition-related expenses, net of tax								27.3			$ 5.7
Acquisition-related costs
Net income						(5.8)
Net income attributable to Amphenol Corporation shareholders						$ (5.8)
Net income (loss) per common share—Diluted (in dollars per share)			$ (0.01)			$ (0.02)
Operating income						$ (6.3)
Acquisition-related expenses			$ 4.0
Acquisition-related expenses, net of tax			3.7
Acquisition-related costs | FCI Asia Pte Ltd (“FCI”)
Net income								(27.3)
Net income attributable to Amphenol Corporation shareholders								$ (27.3)
Net income (loss) per common share—Diluted (in dollars per share)								$ (0.09)
Operating income								$ (30.3)
Impact of ASU 2016-09
Income tax expense (benefit)	$ (20.8)	(16.6)	$ (21.2)	(8.0)					$ (66.6)
Net income		16.6		8.0
Net income attributable to Amphenol Corporation shareholders		$ 16.6		$ 8.0
Net income (loss) per common share—Diluted (in dollars per share)	$ 0.07	$ 0.05	$ 0.07	$ 0.02