STOCK-BASED COMPENSATION Stock Option Activity (Detail)	9 Months Ended
	Sep. 30, 2015 $ / shares shares
Number of Shares
Options outstanding at beginning of period (in shares) | shares	2,948,874
Granted (in shares) | shares	0
Exercised (in shares) | shares	(21,770)
Cancelled (in shares) | shares	(121,492)
Options outstanding at end of period (in shares) | shares	2,805,612
Option Exercise Price
Granted, lower limit (in dollars per share)	$ 0
Granted, upper limit (in dollars per share)	0
Exercised, lower limit (in dollars per share)	5.0
Exercised, upper limit (in dollars per share)	10.0
Cancelled, lower limit (in dollars per share)	5.5
Cancelled, upper limit (in dollars per share)	17.11
Weighted Average Exercise Price
Granted (in dollars per share)	0.00
Exercised (in dollars per share)	6.51
Cancelled (in dollars per share)	$ 12.37