Condensed Financial Information - Balance Sheets (Parenthetical) (Detail) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements Captions [Line Items]
Preferred stock, par value	$ 0.10	$ 0.10
Preferred stock, authorized shares	1,000,000	1,000,000
Preferred stock, issued shares	0	0
Common stock, par value	$ 0.10	$ 0.10
Common stock, authorized shares	50,000,000	50,000,000
Common stock, issued shares	17,942,269	17,792,846
Treasury stock, shares	3,511,380	3,511,380
Parent Company
Condensed Financial Statements Captions [Line Items]
Preferred stock, par value	$ 0.10	$ 0.10
Preferred stock, authorized shares	1,000,000	1,000,000
Preferred stock, issued shares	0	0
Common stock, par value	$ 0.10	$ 0.10
Common stock, authorized shares	50,000,000	50,000,000
Common stock, issued shares	17,942,269	17,792,846
Treasury stock, shares	3,511,380	3,511,380