Shareholder's Equity - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	12 Months Ended			12 Months Ended
	Jun. 30, 2007	Dec. 31, 2013	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2013 Convertible Note	Dec. 31, 2012 Convertible Note	Dec. 31, 2013 Stock Option	Dec. 31, 2012 Stock Option	Dec. 31, 2011 Stock Option
Shareholders Equity [Line Items]
Common shares, authorized		200,000,000
Common shares, par value		$ 1		$ 1
Preference shares, authorized		500,000
Repurchase of outstanding common stock, authorized amount	$ 300
Average market price of common stock		$ 61.32
Weighted average antidilutive which were not included in the calculation of earnings per share					1,600,000	300,000	7,700,000	9,000,000	8,800,000
Strike price of warrants		$ 74.65	$ 74.65
Conversion of convertible notes, shares issued upon conversion		600,000	7,981,422