Commitments and Contingencies (Details) (USD $)	6 Months Ended	12 Months Ended		35 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2013
Commitments [Line Items]
Capital expenditure incurred	$ 623,000	$ 7,081,000	$ 12,664,000	$ 20,368,000
NTIA reimbursements received	831,000	5,745,000	6,945,000	13,521,000
Capital expenditure pending reimbursement from NTIA	725,000	1,100,000	1,920,000	725,000
National Telecommunications Information Administration Broadband Technology Opportunities Program [Member]
Commitments [Line Items]
Approximate amount of capital expenditure for advanced high-capacity broadband network pursuant to Broadband Technology Opportunities Program (BTOP) grant	24,000,000
Approximate amount of reimbursement pursuant to NTIA Grant	16,800,000
Estimated Investment on Project	7,200,000
Estimated Investment On Project Percentage	30.00%
Project Completion Date	Jul. 31, 2013
National Telecommunications Information Administration Broadband Technology Opportunities Program [Member] | Minimum [Member]
Commitments [Line Items]
Approximate amount of capital expenditure for advanced high-capacity broadband network pursuant to Broadband Technology Opportunities Program (BTOP) grant	22,000,000
Estimated Investment on Project	6,600,000
National Telecommunications Information Administration Broadband Technology Opportunities Program [Member] | Maximum [Member]
Commitments [Line Items]
Approximate amount of capital expenditure for advanced high-capacity broadband network pursuant to Broadband Technology Opportunities Program (BTOP) grant	23,000,000
Estimated Investment on Project	$ 6,900,000