STOCK-BASED COMPENSATION PLANS - Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Options
Outstanding, beginning of period (in shares)	983,512	1,098,823	1,097,323
Granted (in shares)	82,580	65,522	94,115
Exercised (in shares)	(582,303)	(166,838)	(83,790)
Canceled (in shares)	(17,112)	(13,995)	(8,825)
Outstanding, end of period (in shares)	466,677	983,512	1,098,823
Exercisable at December 31, 2017	283,169
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 32.52	$ 35.39	$ 32.70
Granted (in dollars per share)	77.54	86.91	61.39
Exercised (in dollars per share)	28.29	21.37	25.58
Canceled (in dollars per share)	69.76	76.89	71.47
Outstanding, end of period (in dollars per share)	61.04	$ 32.52	$ 35.39
Exercisable at December 31, 2017 (in dollars per share)	$ 50.60
Weighted Average Remaining Contractual Life
Weighted- Average Remaining Contractual Life, outstanding	5 years 8 months	4 years	4 years 3 months	4 years 9 months
Weighted Average Remaining Contractual Life, Exercisable shares at December 31, 2017	4 years 7 months
Aggregate Intrinsic Value
Outstanding, beginning of period	$ 40,137	$ 52,332	$ 42,154
Granted	0	0	2,035
Exercised	(24,433)	(10,020)	(4,813)
Canceled	(8)	(64)	(102)
Outstanding, end of period	4,298	$ 40,137	$ 52,332
Exercisable at December 31, 2017	$ 5,564