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								12 Months Ended
	Mar. 31, 2018	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Mar. 31, 2018	Apr. 01, 2017	Apr. 02, 2016
Numerator:
Net income attributable to MKHL	$ 44.1	$ 219.4	$ 202.9	$ 125.5	$ (26.8)	$ 271.3	$ 160.9	$ 147.1	$ 591.9	$ 552.5	$ 839.1
Denominator:
Basic weighted average shares (in shares)	150,818,144	152,047,963	151,781,340	154,486,898	159,944,132	163,148,597	166,695,631	174,158,571	152,283,586	165,986,733	186,293,295
Weighted average dilutive share equivalents:
Share options and restricted shares/units, and performance restricted share units (in shares)									2,819,299	2,137,080	2,760,994
Diluted weighted average shares (in shares)	154,252,751	154,623,339	154,168,094	156,871,518	161,827,486	165,214,045	168,839,967	176,613,751	155,102,885	168,123,813	189,054,289
Basic net income per share (in dollars per share)									$ 3.89	$ 3.33	$ 4.50
Diluted net income per share (in dollars per share)									$ 3.82	$ 3.29	$ 4.44