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Commitments and Contingencies - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 29, 2015
Other Commitments [Line Items]      
Outstanding letter of credit, amount $ 1,100,000 $ 1,100,000  
Outstanding performance and payment of bonds     $ 5,000,000
Amounts drawn against outstanding letters of credit or performance bond 0 0  
Restricted Escrow Deposits 1,000,000 1,000,000  
Performance Bonds [Member]      
Other Commitments [Line Items]      
Outstanding performance and payment of bonds $ 8,200,000 $ 4,000,000