Consolidation and Nature of Operations (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Jul. 03, 2018
Cash paid during the period for:
Income taxes, net of refunds	$ 10,091	$ 2,185
Interest, net of amounts capitalized	161,875	147,149
Significant non-cash investing and financing activities:
Accrued capital expenditures	99,405	93,031
Sale of 4CA's 7% interest in Four Corners	68,907	0
APS
Cash paid during the period for:
Income taxes, net of refunds	24,746	132
Interest, net of amounts capitalized	154,788	142,779
Significant non-cash investing and financing activities:
Accrued capital expenditures	$ 99,405	$ 94,769
APS | Four Corners
Investment [Line Items]
Ownership percentage	7.00%		7.00%