INCOME TAXES - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
INCOME TAXES
Income taxes at statutory rate	$ 106,454	$ 172,434	$ 137,547
Less: Income taxes at statutory rate on Partnership income not subject to income taxes	(107,594)	(173,322)	(139,107)
Increase/(decrease) resulting from:
State taxes, net of federal income tax	(123)	(112)	(192)
Change in valuation allowance for deferred tax assets	1,557	1,636	3,483
Other	(273)	$ (636)	(334)
Income tax expense	$ 21		$ 1,397