Acquisitions - Additional Information (Detail)			3 Months Ended								9 Months Ended	12 Months Ended
	Sep. 30, 2019 USD ($)	Dec. 07, 2018 USD ($) $ / shares shares	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jul. 01, 2018 USD ($)	Dec. 30, 2018 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($) acquisition
Business Acquisition [Line Items]
Goodwill			$ 663,936,000				$ 656,399,000					$ 663,936,000	$ 656,399,000	$ 352,805,000
Estimated tax-deductible goodwill			120,708,000				58,699,000					120,708,000	58,699,000
Number of businesses acquired | acquisition														0
Net sales			781,803,000	$ 763,698,000	$ 762,137,000	$ 780,230,000	796,603,000	$ 680,022,000	$ 660,462,000	$ 670,930,000		3,087,868,000	2,808,017,000	$ 2,581,891,000
Net loss			1,523,000	$ (27,305,000)	(62,698,000)	$ (48,636,000)	$ (18,546,000)	$ (48,614,000)	$ (47,447,000)	$ (46,020,000)		(137,116,000)	(160,627,000)	$ (119,833,000)
NorthStar
Business Acquisition [Line Items]
Payments to acquire businesses	$ 77,777,000
Debt assumed	107,018,000				107,018,000
Goodwill	73,788,000				73,788,000
NorthStar | Developed Technology Rights [Member]
Business Acquisition [Line Items]
Acquired intangible assets	$ 19,000,000
Estimated useful lives of finite-lived assets	10 years
NorthStar | Trademarks
Business Acquisition [Line Items]
Acquired intangible assets	$ 6,000,000
Estimated useful lives of finite-lived assets	5 years
Estimated tax-deductible goodwill	$ 72,056,000				$ 72,056,000
NorthStar | Customer relationships
Business Acquisition [Line Items]
Acquired intangible assets	$ 9,000,000
Alpha
Business Acquisition [Line Items]
Payments to acquire businesses		$ 650,000,000
Debt assumed		145,304,000
Goodwill		319,228,000
Estimated tax-deductible goodwill			$ 33,926,000									33,926,000
Initial purchase consideration		750,000,000
Consideration transferred		742,502,000
Acquisition cost expensed												12,883,000
Inventory adjustment												$ 7,263,000
Shares issued in acquisition, value		$ 93,268,000
Closing day spot rate (USD per share) | $ / shares		$ 79.20
Working capital adjustment		$ 766,000
Shares issued in acquisition (USD per share) | $ / shares		$ 84.92
Net sales													162,454,000
Net loss													$ 1,252,000
Alpha | Customer relationships
Business Acquisition [Line Items]
Acquired intangible assets		$ 221,000,000
Minimum
Business Acquisition [Line Items]
Estimated useful lives of finite-lived assets													3 years
Minimum | NorthStar | Customer relationships
Business Acquisition [Line Items]
Estimated useful lives of finite-lived assets	15 years
Maximum
Business Acquisition [Line Items]
Estimated useful lives of finite-lived assets													20 years
Consideration transferred											$ 250,000,000
Maximum | NorthStar | Customer relationships
Business Acquisition [Line Items]
Estimated useful lives of finite-lived assets	18 years
Trademarks | Alpha
Business Acquisition [Line Items]
Acquired indefinite-lived intangible assets		$ 56,000,000
Common Stock | Alpha
Business Acquisition [Line Items]
Shares issued in acquisition (in shares) | shares		1,177,630