Consolidation and Nature of Operations (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash paid during the period for:
Income taxes, net of refunds	$ 12,488	$ 10,091
Interest, net of amounts capitalized	166,907	161,875
Significant non-cash investing and financing activities:
Accrued capital expenditures	85,099	99,405
Right-of-use operating lease assets obtained in exchange for operating lease liabilities	8,759	0
Sale of 4CA's 7% interest in Four Corners	0	68,907
APS
Cash paid during the period for:
Income taxes, net of refunds	35,573	24,746
Interest, net of amounts capitalized	157,593	154,788
Significant non-cash investing and financing activities:
Accrued capital expenditures	85,099	99,405
Right-of-use operating lease assets obtained in exchange for operating lease liabilities	$ 8,759	$ 0
APS | Four Corners
Significant non-cash investing and financing activities:
Ownership percentage	7.00%