GENERAL (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Supplementary cash flows information:
Interest paid (net of interest capitalized)				$ 95,366	$ 93,803
Income taxes paid — net				20,796	40,776
Supplementary non-cash investing and financing activities:
Additions to property, plant and equipment and other long-lived assets	[1]			100,390	70,737
Allowance for equity funds used during construction		$ 8,921	$ 7,464	$ 16,440	$ 15,013

[1] Amounts consist of accrued liabilities for construction, labor, materials and other costs that have not been included in investing activities. These amounts have not been paid for as of June 30, 2016 or 2015, respectively, but have been or will be included as a cash outflow from investing activities for expenditures for property, plant and equipment when paid.