Shareholders' Equity - Common Dividends Declared Per Share (Detail) (Common stock, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Dividends Per Share [Line Items]
Dividends declared per common share	$ 2.3	$ 2.74046	[1]
December 17, 2013
Dividends Per Share [Line Items]
Date declared	Dec. 17, 2013
Dividends declared per common share	$ 0.50
Date of Payment	Jan. 28, 2014
September 16, 2013
Dividends Per Share [Line Items]
Date declared	Sep. 16, 2013
Dividends declared per common share	$ 0.50
Date of Payment	Oct. 28, 2013
June 17, 2013
Dividends Per Share [Line Items]
Date declared	Jun. 17, 2013
Dividends declared per common share	$ 0.65
Date of Payment	Jul. 26, 2013
March 19, 2013
Dividends Per Share [Line Items]
Date declared	Mar. 19, 2013
Dividends declared per common share	$ 0.65
Date of Payment	Apr. 26, 2013
December 14, 2012
Dividends Per Share [Line Items]
Date declared		Dec. 14, 2012
Dividends declared per common share		$ 0.65
Date of Payment		Jan. 28, 2013
September 13, 2012
Dividends Per Share [Line Items]
Date declared		Sep. 13, 2012
Dividends declared per common share		$ 0.65
Date of Payment		Oct. 29, 2012
June 14, 2012
Dividends Per Share [Line Items]
Date declared		Jun. 14, 2012
Dividends declared per common share		$ 0.65
Date of Payment		Jul. 27, 2012
March 15, 2012
Dividends Per Share [Line Items]
Date declared		Mar. 15, 2012
Dividends declared per common share		$ 0.65
Date of Payment		Apr. 27, 2012

[1] Includes common stock dividend of $0.140460 undistributed taxable income carried-forward from fiscal tax year 2011.