Investments - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) Securities	Dec. 31, 2017 USD ($) Securities
Schedule of Available-for-sale Securities [Line Items]
Short-term Investments	$ 12,868	$ 24,965
Number of securities in unrealized loss position | Securities	20	27
Proceeds from sale of investment in fixed maturity securities	$ 17,100	$ 5,800
Investments on deposit with the state insurance department	4,100
Time Deposits	$ 8,100