Organization and Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) subsidiary segment	Dec. 31, 2017 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of wholly owned subsidiaries | subsidiary	2
Number of reportable segments | segment	2
Warranty period	1 year
Corporate owned life insurance policies fair value | $	$ 3,804	$ 3,846