Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ 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
Selected Quarterly Financial Data (Unaudited)
Net sales	$ 1,943.9	$ 1,840.8	$ 1,666.5	$ 1,560.1	$ 1,651.1	$ 1,635.9	$ 1,548.2	$ 1,451.2	$ 7,011.3	$ 6,286.4	$ 5,568.7
Gross Profit	635.4	606.1	552.6	515.9	546.1	537.3	497.3	459.2	2,309.9	2,040.0	1,779.5
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
Net income (loss)	(100.4)	280.3	253.6	227.3	238.3	227.1	208.7	158.4	660.7	832.6	772.3
Net income (loss) 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 — Basic (in dollars per share)	$ (0.34)	$ 0.91	$ 0.82	$ 0.73	$ 0.76	$ 0.73	$ 0.67	$ 0.51	$ 2.13	$ 2.67	$ 2.47
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