Discontinued Operations - Summary of Financial Information for Fiber Optic Licensing Operations (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015
Discontinued Operations, Disposed of by Sale
Net income from discontinued operations as presented in the statements of operations	$ 14,102	$ 19,897
Fiber Optic Licensing Division [Member]
Discontinued Operations, Disposed of by Sale
Revenues	25,692	51,262
Cost of services (including depreciation)	10,896	21,711
Selling, general and administrative expenses	5,106	9,881
Amortization of intangible assets	413	825
Other income (expense) items that are not major	9	10
Income before taxes of discontinued operations	9,286	18,855
Provision for income taxes related to discontinued operations	(4,816)	(1,042)
Net income from discontinued operations as presented in the statements of operations	$ 14,102	$ 19,897