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Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended				6 Months Ended		9 Months Ended				12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018		Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	[1]	Jun. 30, 2019	Jun. 30, 2018
Income Tax Contingency [Line Items]
U.S. federal statutory rate						35.00%	21.00%	21.00%				28.00%
Tax Act, incomplete accounting, provisional adjustments				$ (32,600,000)
Earnings per share increase				$ 0.45
Tax Act, limitation on deduction of executive compensation					$ 1,000,000		$ 1,000,000
Tax Act, incomplete accounting, transition tax for accumulated foreign earnings, provisional income tax expense							0
Income tax expense (benefit)	$ (3,600,000)	$ 4,300,000	[1]				$ (1,000,000)		$ (16,700,000)
Approximate rate on pre-tax income	(109.10%)	32.30%
State Tax Authority [Member] | Earliest Tax Year [Member] | State of New Jersey [Member]
Income Tax Contingency [Line Items]
Tax year being audited in income tax examination							2013
State Tax Authority [Member] | Latest Tax Year [Member] | State of New Jersey [Member]
Income Tax Contingency [Line Items]
Tax year being audited in income tax examination							2017
Foreign Tax Authority | Earliest Tax Year [Member] | Federal Ministry of Finance, Germany [Member]
Income Tax Contingency [Line Items]
Tax year being audited in income tax examination							2013
Foreign Tax Authority | Latest Tax Year [Member] | Federal Ministry of Finance, Germany [Member]
Income Tax Contingency [Line Items]
Tax year being audited in income tax examination							2015
Scenario, Plan [Member]
Income Tax Contingency [Line Items]
U.S. federal statutory rate											21.00%
[1] Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606). See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

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