Income Per Share - Weighted Average Number of Common Shares Outstanding (Detail) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Line Items]
Weighted average shares outstanding - basic	50,524	46,546	51,392	48,073
Effect of dilutive stock-based compensation	460		503
Effect of convertible notes	5,416		6,187
Effect of common stock warrants	3,702		4,631
Weighted average shares outstanding - diluted	60,102	46,546	62,713	48,073