INCOME TAXES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current:
Federal	$ 68,667	$ 59,053	$ 54,778
State	11,335	9,936	9,259
Foreign	7,534	4,391	3,883
Total current tax	87,536	73,380	67,920
Deferred:
Federal	1,286	6,123	(468)
State	2,078	2,159	730
Foreign	129	158	94
Total deferred tax	3,493	8,440	356
TOTAL PROVISION FOR INCOME TAXES	91,029	81,820	68,276
Reconciliation of primary factors causing income tax expense to be different than the federal statutory rate
Income tax at statutory rate	85,112	76,820	67,063
State income tax expense (net of federal benefit)	8,377	7,429	6,498
Foreign tax benefit	(1,729)	(1,760)	(2,661)
Other	(731)	(669)	(2,624)
TOTAL PROVISION FOR INCOME TAXES	$ 91,029	$ 81,820	$ 68,276
Effective income tax rate (as a percent)	37.40%	37.30%	35.60%
Income taxes paid net of refunds	$ 82,690	$ 74,454	$ 69,354