Supplemental Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2016

Supplemental Cash Flow Information [Abstract]

Schedule of Cash Flow, Supplemental Disclosure

Supplemental Cash Flow Information

	Year Ended December 31,
In thousands	2016			2015			2014
Supplemental cash flow information
Cash paid for interest, expensed	$	130,843		$	146,560		$	185,140
Cash paid for interest, capitalized	25,982			32,146			24,202
Cash paid for interest, treated as a reduction of debt	25,835			—			—
Cash paid for income taxes	375			6,340			5,033
Cash received from income tax refunds	(2,455		)	(50,163		)	(13,193		)
Noncash investing and financing activities
Increase in asset retirement obligations	11,621			14,866			6,500
Increase (decrease) in liabilities for capital expenditures	(13,593		)	(97,278		)	215
Retirement of treasury stock	—			884,129			—