CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Net sales	$ 6,751,552	$ 6,114,999	$ 19,030,244	$ 18,000,337
Cost of sales	6,305,224	5,698,544	17,783,659	16,864,196
Gross profit	446,328	416,455	1,246,585	1,136,141
Selling, general and administrative expenses	247,365	231,551	772,325	715,040
Intangible amortization	19,588	18,734	55,865	62,318
Interest and other, net	31,350	22,838	85,780	71,869
Other charges (income), net	6,865	3,090	(172,467)	15,007
Income before income taxes	141,160	140,242	505,082	271,907
Provision for income taxes	22,827	10,773	56,953	39,217
Net income	$ 118,333	$ 129,469	$ 448,129	$ 232,690
Earnings per share:
Basic (in dollars per share)	$ 0.22	$ 0.24	$ 0.85	$ 0.43
Diluted (in dollars per share)	$ 0.22	$ 0.24	$ 0.84	$ 0.42
Weighted-average shares used in computing per share amounts:
Basic (in shares)	528,405	539,638	529,984	542,780
Diluted (in shares)	534,352	545,022	535,972	548,372