Shareholders' Equity - Additional Information (Detail) - USD ($)	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Equity Class Of Treasury Stock [Line Items]
Common shares, shares authorized	75,000,000		75,000,000
Common shares, par value	$ 0.01		$ 0.01
Common shares, shares outstanding	27,065,852		27,129,832
Treasury stock, shares	25,899,945		25,835,965
Cost of shares repurchased under common stock repurchase program	$ 66,000
Preferred shares, shares issued	3,677		3,677
Preferred shares, shares outstanding	3,677		3,677
Preferred shares, par value	$ 0.01
Preferred shares, liquidation preference	$ 3,677,000		$ 3,677,000
Common Stock
Equity Class Of Treasury Stock [Line Items]
Number of common stock shares repurchased	63,980
Cost of shares repurchased under common stock repurchase program	$ 66,000
Share repurchase program, extended date	Dec. 31, 2017
Common Stock | Maximum
Equity Class Of Treasury Stock [Line Items]
Common stock shares repurchase amount		$ 5,000,000