Company's Stock Option Activity (Detail) shares in Thousands	9 Months Ended
	Sep. 30, 2015 $ / shares shares
Options
Outstanding at January 1, 2015 | shares	9,493
Stock Options, Granted | shares	54
Stock Options, Exercised | shares	(737)
Stock Options, Forfeited | shares	(297)
Stock Options, Cancelled | shares	(72)
Outstanding at September 30, 2015 | shares	8,441
Options exercisable at September 30, 2015 | shares	5,075
Weighted Average Exercise Price
Weighted Average Exercise Price, Outstanding at January 1, 2015	$ 6.88
Weighted Average Exercise Price, Granted	9.19
Weighted Average Exercise Price, Exercised	4.71
Weighted Average Exercise Price, Forfeited	7.93
Weighted Average Exercise Price, Cancelled	12.61
Weighted Average Exercise Price, Outstanding at September 30, 2015	6.99
Weighted Average Exercise Price, Options exercisable at September 30, 2015	5.85
Weighted Average Exercise Price, Weighted-average fair value of options granted during the period	$ 6.80