Consolidation and Nature of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash paid during the period for:
Income taxes, net of refunds	$ 2,502	$ 1,832
Interest, net of amounts capitalized	56,139	53,555
Significant non-cash investing and financing activities:
Accrued capital expenditures	$ 59,707	$ 56,165