Reconciliation of Weighted Average Shares Used in Calculating Basic and Diluted Earnings Per Share (Detail) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share Disclosure [Line Items]
Basic	47,991	53,325	48,682	57,966
Effect of exercise of stock options	987	1,158	1,036	1,123
Effect of assumed vesting of performance related to restricted stock-based awards	381	180	127	60
Effect of assumed vesting of restricted stock	1,387	1,489	1,369	1,450
Effect of convertible notes subject to conversion	5,753	1,653	5,411	551
Effect of convertible notes warrants subject to conversion	1,958		1,681
Diluted	58,457	57,805	58,306	61,150