Consolidated Statements of Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2013 Restated [Member]	Sep. 30, 2013 Restated [Member]	Sep. 30, 2013 Non-affiliates [Member] Restated [Member]	Sep. 30, 2013 Non-affiliates [Member] Restated [Member]	Sep. 30, 2013 Affiliates [Member] Restated [Member]	Sep. 30, 2013 Affiliates [Member] Restated [Member]
Operating revenues
Operating revenues, non-affiliates	$ 96,658	$ 272,613	$ 82,427	$ 271,122
Operating revenues, affiliates	92	96	1,414	1,535
Total Operating revenues	96,750	272,709	83,841	272,657
Operating expenses:
Cost of services and sales					33,078	105,412	11,642	11,959
Selling, general and administrative	25,437	80,374	29,274	83,717
Depreciation and amortization	12,932	38,452	9,209	33,291
(Gain) loss on disposal of assets, net	(2,559)	(2,140)	(207,003)	(206,377)
Earnings from equity method investments	(45)	(45)	(8,082)	(8,061)
Total operating expenses (income)	72,111	228,243	(131,882)	19,941
Operating income	24,639	44,466	215,723	252,716
Other income and expense:
Interest expense	(10,268)	(29,203)	(9,785)	(29,970)
Loss on extinguishment of debt		(323)	(2,094)	(2,370)
Interest income	9	31	19	37
Other				(13)
Total other income and expense	(10,259)	(29,495)	(11,860)	(32,316)
Income before income tax expense	14,380	14,971	203,863	220,400
Income tax expense	(6,136)	(6,385)	(83,956)	(59,331)
Net income	8,244	8,586	119,907	161,069
Other comprehensive income (loss):
Minimum pension liability adjustment	199	541	205	612
Income tax effect	(82)	(222)	(84)	(252)
Interest rate swap marked to fair value	314	(2,209)	1,348	3,290
Income tax effect	(129)	907	(554)	(1,353)
Total other comprehensive income (loss)	302	(983)	915	2,297
Total comprehensive income	$ 8,546	$ 7,603	$ 120,822	$ 163,366
Net income per share:
Basic	$ 0.18	$ 0.19	$ 2.54	$ 3.46
Diluted	$ 0.17	$ 0.19	$ 2.05	$ 2.81
Weighted average shares outstanding:
Basic	45,664	45,511	47,159	46,592
Diluted	59,437	45,806	59,346	58,816
Cash dividends declared per common share	$ 0.05	$ 0.15