Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2016

Quarterly Financial Data [Abstract]

Schedule Of Quarterly Financial Information

	Quarter Ended
	December 31,		September 30,		June 30,		March 31,
	2016		2016		2016		2016
	(in thousands, except per share amounts)
Revenues	$	416,505	$	411,319	$	405,532	$	399,769
Operating income		107,430		108,210		74,066		97,602
Depreciation, accretion, and amortization		(158,554)		(160,111)		(159,723)		(159,801)
Loss from extinguishment of debt, net		(18,189)		(34,512)		—		—
Net income (loss)		5,256		(15,370)		32,711		53,641
Net income (loss) per common share - basic	$	0.04	$	(0.12)	$	0.26	$	0.43
Net income (loss) per common share - diluted		0.04		(0.12)		0.26		0.43
	Quarter Ended
	December 31,		September 30,		June 30,		March 31,
	2015		2015		2015		2015
	(in thousands, except per share amounts)
Revenues	$	406,941	$	410,735	$	410,704	$	410,094
Operating income		82,129		43,083		98,163		89,081
Depreciation, accretion, and amortization		(161,461)		(164,330)		(162,377)		(171,853)
Loss from extinguishment of debt, net		(783)		—		—		—
Net income (loss)		31,019		(155,946)		28,305		(79,034)
Net income (loss) per common share - basic	$	0.25	$	(1.23)	$	0.22	$	(0.61)
Net income (loss) per common share - diluted		0.24		(1.23)		0.22		(0.61)