Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income tax allocation [Abstract]
Income tax expense on continuing operations	$ 19,878	$ 12,008	$ 10,667
Income tax benefit on discontinued operations	0	(196)	(359)
Shareholder's equity, for compensation expense for tax purposes in excess of amounts recognized for financial report purposes	(101)	(106)	(5)
Other comprehensive income for changes in cash flow hedge	2,315	(574)
Income tax expense continuing operations and discontinued operations	22,092	11,132	10,303
Current expense (benefit) [Abstract]
Federal taxes	3,404	3,741	(8,539)
State taxes	2,305	1,868	3,233
Total current provision (benefit)	5,709	5,609	(5,306)
Deferred expense (benefit) [Abstract]
Federal taxes	12,317	5,618	15,749
State taxes	1,852	781	224
Total deferred provision	14,169	6,399	15,973
Income tax expense on continuing operations	19,878	12,008	10,667
Reconciliation of income taxes [Abstract]
Computed "expected" tax expense at 35%	17,312	10,014	8,472
State income taxes, net of federal tax effect	2,702	1,722	2,247
Other, net	(136)	272	(52)
Income tax expense on continuing operations	19,878	12,008	10,667
Federal statutory income tax rate (in hundredths)	35.00%
Deferred tax assets [Abstract]
Lease obligations	2,139	1,374
Deferred activation charges	107	105
Allowance for doubtful accounts	370	441
Inventory reserves	259	244
State net operating loss carry-forwards, net of federal tax	650	782
Accrued pension costs	1,018	879
Loss on investments, net	0	438
Accrued compensation costs	1,140	996
Asset retirement obligations	2,601	2,356
Intangible assets	7,757	7,966
Goodwill	2,660	4,091
Deferred revenues	1,873	1,401
Other, net	0	549
Total gross deferred tax assets	20,574	21,622
Less valuation allowance	(591)	(538)
Net deferred tax assets	19,983	21,084
Deferred tax liabilities [Abstract]
Plant and equipment	84,772	72,747
Franchise rights	5,942	4,211
Section 481a deferred revenues	493	737
Deferred financing costs	128	453
Prepaid insurance	241	0
Gain on investments, net	115	0
Other, net	1,876	0
Total gross deferred tax liabilities	93,567	78,148
Net deferred tax liabilities	73,584	57,064
Increase in valuation allowance	53
Deferred tax asset related to various state net operating losses net of valuation allowance	59
Unrecognized tax benefits	$ 0	$ 0