Orange County-Poughkeepsie Limited Partnership (Summarized O-P Income Statement Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Schedule of Equity Method Investments [Line Items]
Company share	$ 3,250	$ 3,096	$ 6,500	$ 4,521
O-P [Member]
Schedule of Equity Method Investments [Line Items]
Net sales	81,176	76,180	161,068	150,416
Cellular service cost	36,307	34,305	72,287	70,353
Operating expenses	22,237	20,755	43,635	41,375
Operating income	22,632	21,120	45,146	38,688
Other income	4	4	7	6
Net income	22,636	21,124	45,153	38,694
Company share	$ 1,835	$ 1,713	$ 3,661	$ 3,137