Assets Held for Sale and Discontinued Operations (Details) (USD $)	3 Months Ended				3 Months Ended			12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Nov. 28, 2012	Mar. 31, 2013 Blackfoot Telecommunications Group [Member]		Mar. 31, 2012 Blackfoot Telecommunications Group [Member]	Dec. 31, 2012 Blackfoot Telecommunications Group [Member] employee
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross cash proceeds				$ 30,300,000
Number of employees retained								11
Deferred income taxes	(21,428,000)	(24,373,000)			6,700,000
Recorded gain, net of tax					16,800,000
Gross gain on sale for income tax purposes					27,500,000
Assets held for sale:
Accounts receivable, net								261,000
Prepaid expenses								37,000
Other current assets								3,000
Property, plant and equipment (net of $4.6 million accumulated depreciation)								6,441,000
Accumulated depreciation								4,600
Other assets								5,807,000
Total assets held for sale	0		12,549,000					12,549,000
Liabilities held for sale:
Accounts payable								137,000
Other accrued liabilities								148,000
Other long-term liabilities								122,000
Total liabilities held for sale	0		407,000					407,000
Income Statement Disclosures:
Revenue					674,000	[1]	2,058,000
Income before income taxes					$ 477,000	[1]	$ 838,000

[1] Reflects revenue and income before income taxes of the Idaho-based operations for the period of January 1, 2013 through the completion of the transaction on January 31, 2013.