Earnings Per Share (Outstanding Common Stock Equivalents That Were Anti-Dilutive) (Parenthetical) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Exercise price for warrants outstanding	$ 22.5	$ 22.5	$ 22.5	$ 22.5
3 1/2% Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Convertible senior notes interest percentage	3.50%	3.50%	3.50%	3.50%