Income Per Share - Weighted Average Number of Common Shares Outstanding (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Weighted average shares outstanding - basic	51,269	50,814	51,196	50,719
Effect of dilutive stock-based compensation	332	464	366	519
Effect of convertible notes		6,033		5,798
Effect of common stock warrants		3,224		3,042
Weighted average shares outstanding - diluted	51,601	60,535	51,562	60,078