Orange County-Poughkeepsie Limited Partnership (Summarized O-P Income Statement Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule of Equity Method Investments [Line Items]
Company share	$ 3,250	$ 1,425
O-P [Member]
Schedule of Equity Method Investments [Line Items]
Net sales	79,892	74,235
Cellular service cost	35,980	36,047
Operating expenses	21,398	20,620
Operating income	22,514	17,568
Other income (expense)	3	3
Net income	22,517	17,571
Company share	$ 1,826	$ 1,425