Investments (Detail) (USD $)	3 Months Ended		1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	May 31, 2014	Dec. 31, 2014	Aug. 31, 2013	Jan. 31, 2013	Jan. 31, 2015 director
Sales of marketable securities	$ 6,773,000	$ 40,579,000
Derivative liability	166,089,000			181,138,000
Realized loss on financial instrument obligation	(200,000)
Loss on change to equity method at fair value	2,807,000	0
Value of investment	33,240,000			26,871,000
Cost-method investments	28,483,000			28,525,000
Venture Capital Funds
Other investments	500,000
Promissory Note
Other investments	3,000,000
Again Faster
Membership interest (as a percent)					44.70%	40.00%
Ownership (as a percent)	40.00%			40.00%
iGo
Ownership (as a percent)	46.90%			46.90%
Value of investment	3,300,000
API
Ownership (as a percent)	20.60%		20.60%	20.60%
Number of shares held			11,377,192
Number of shares purchased			1,666,666
Loss on change to equity method at fair value	600,000
Aviat Networks, Inc.
Ownership (as a percent)	12.90%						12.90%
Number of shares held							8,041,892
Number of directors							2
Number of directors on board							8
Partnership
Cost-method investments	25,000,000
Fair value of cost method investments	$ 26,700,000