Share Capital and Share Repurchases - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	26 Months Ended
	May 31, 2011	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012
Equity, Class of Treasury Stock [Line Items]
Common stock, authorized shares			50,000,000	50,000,000
Common stock, par value			$ 0.10	$ 0.10
Preferred stock, authorized shares			1,000,000	1,000,000
Preferred stock, par value			$ 0.10	$ 0.10
Share repurchase program, authorized amount	$ 50	$ 150