Investments (Detail) (USD $)	12 Months Ended			1 Months Ended	0 Months Ended	1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 31, 2013	Jul. 11, 2013 director	May 31, 2014	Jan. 31, 2015 director	Aug. 23, 2013
Schedule of Equity Method Investments [Line Items]
Loss on financial instrument obligations	$ 1,821,000	$ 0	$ 0
Proceeds from sales of marketable securities	116,314,000	75,825,000	574,074,000
Loss on equity-method investees	6,070,000	862,000	0
Carrying Value	30,060,000	8,339,000
Other investments	28,525,000	25,844,000
Again Faster
Schedule of Equity Method Investments [Line Items]
Cost of acquired entity, cash paid				4,000,000
Again Faster
Schedule of Equity Method Investments [Line Items]
Percentage of voting interests acquired				40.00%
iGo
Schedule of Equity Method Investments [Line Items]
Shares of common stock acquired (in shares)								1,316,866
Total consideration								5,200,000
Ownership	46.90%							44.70%
Number of directors appointed					2
Number of directors on board					4
Partnership
Schedule of Equity Method Investments [Line Items]
Other investments	25,000,000
Fair value	28,600,000
API
Schedule of Equity Method Investments [Line Items]
Ownership						20.60%
Ownership (in shares)						11,377,192
Purchase price, shares issued						1,666,666
Loss recognized	600,000
Subsequent Event | Aviat Networks, Inc.
Schedule of Equity Method Investments [Line Items]
Ownership							12.90%
Ownership (in shares)							8,041,892
Number of directors							2
Expected loss							2,800,000
Venture Capital Funds
Schedule of Equity Method Investments [Line Items]
Other Investments	500,000
Promissory Note
Schedule of Equity Method Investments [Line Items]
Other Investments	$ 3,000,000