Investment in Equity Investee (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2011
Schedule of Equity Method Investments [Line Items]
Equity interest in CONTADO acquisition				19.99%
Equity interest in CONTADO, excess cost of investment over underlying equity in net assets				$ 9,000,000.0
Earnings of equity method investment	$ 936,000	$ 692,000	$ 604,000
Dividends received from CONTADO	500,000	400,000	0
Equity Method Investments
Schedule of Equity Method Investments [Line Items]
Equity interest in CONTADO, amortization expense	$ 300,000	$ 300,000	$ 200,000