Investments - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) Securities	Sep. 30, 2018 Securities
Schedule of Available-for-sale Securities [Line Items]
Document Period End Date	Mar. 31, 2019
Available-for-sale Securities	$ 20,397	$ 22,137
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	2,868	$ 4,743
Number of securities in unrealized loss position | Securities		20	9
Proceeds from sale of investment in fixed maturity securities	1,900
Proceeds from Sale of Other Investments	$ 2,400
Investment security maturity date, start	Jan. 01, 2019
Investment security maturity date, End	Mar. 31, 2019
Gross realized gains and losses of securities	insignificant
Investments on deposit with the state insurance department	$ 4,100
U.S. Treasury securities, obligations of U.S. Government agencies and Municipalities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	20,158	$ 21,514
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	$ 239	$ 623