INCOME TAXES (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]
Income taxes	$ 26,002	$ 23,836
Pre-tax income	82,426	90,679
Effective income tax rate (as a percent)	31.50%	26.30%
Unrecognized tax benefits	22,440
Unrecognized tax benefits that, if recognized, would be reflected as a component of income tax expense	12,574
Reasonably possible reduction in prior years' unrecognized tax benefits during the next twelve months	(4,504)
Possible increase in Canadian federal and provincial tax due to reassessment	56,623
Possible interest on Canadian tax reassessment	15,422
Tax deposit	$ 80,979
Interest percentage charged on tax assessment	5.00%
Rate of interest to be earned on tax deposit upon favorable outcome	1.00%