Summary of Significant Accounting Policies - Components of Calculation of Basic Net Income Per Ordinary Share and Diluted Net Income Per Ordinary Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Numerator:
Net income attributable to MKHL	$ 137.6	$ 202.9	$ 324.0	$ 328.4
Denominator:
Basic weighted average shares (in shares)	149,575,112	151,781,340	149,538,607	153,134,119
Weighted average dilutive share equivalents:
Share options, restricted shares/units, and performance restricted share units (in shares)	2,130,573	2,386,754	2,514,064	2,385,687
Diluted weighted average shares (in shares)	151,705,685	154,168,094	152,052,671	155,519,806
Basic net income per share (in dollars per share)	$ 0.92	$ 1.34	$ 2.17	$ 2.14
Diluted net income per share (in dollars per share)	$ 0.91	$ 1.32	$ 2.13	$ 2.11