Credit Facilities and Debt - Additional Information - Valla Short-Term Working Capital Borrowings (Detail) - Sep. 30, 2018 - Short-term Working Capital Borrowings [Member] - Valla [Member] € in Thousands, $ in Thousands	USD ($) Bank	EUR (€) Bank
Credit Facilities [Line Items]
Line of credit facility, maximum borrowing capacity	$ 1,011	€ 870
Line of credit facility, amount borrowed	$ 459	€ 394
Italy [Member]
Credit Facilities [Line Items]
Number of Italian banks	2	2
Minimum [Member] | Italy [Member]
Credit Facilities [Line Items]
Working capital borrowing interest rate	4.50%	4.50%
Maximum [Member] | Italy [Member]
Credit Facilities [Line Items]
Working capital borrowing interest rate	4.75%	4.75%