Discontinued Operations (Details Textual) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Discontinued Operations (Textual) [Abstract]
Loss before taxes		$ (1,145,000)	$ (11,769,000)	$ (30,379,000)
Recognized after-tax gain	44,847,000		44,847,000
Trapeze Networks, Inc. [Member]
Discontinued Operations (Textual) [Abstract]
Proceeds from the sale of Trapeze			152,100,000
Recognized pre-tax gain			88,300,000
Amount received in cash at the end of transaction			136,900,000
Amount in escrow as partial security for Company's indemnity obligations under transaction's purchase and sale agreement			15,200,000
Loss before taxes		(196,000)	(10,791,000)	(28,324,000)
Recognized after-tax gain		0	44,800,000
Communications cable operation in Phoenix, Arizona [Member]
Discontinued Operations (Textual) [Abstract]
Losses, including interest expense, related to discontinued operations, net of tax		700,000	600,000	1,400,000
Loss before taxes		$ (949,000)	$ (978,000)	$ (2,055,000)