DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES - AOCI (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), at beginning of period	$ 966,589	$ 1,297,347
Accumulated other comprehensive income (loss), at end of period	1,143,712	1,295,072
Amount of derivatives reclassified out of AOCI	2,234
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), at beginning of period	(509)	(2,519)
Other comprehensive income (loss) before reclassifications	794	(9,033)
Amounts reclassified from accumulated other comprehensive income (loss)	758	1,108
Net current period other comprehensive income (loss)	1,552	(7,925)
Accumulated other comprehensive income (loss), at end of period	$ 1,043	$ (10,444)