Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, with jurisdictional netting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32537-109319

Summary of Significant Accounting Policies - Goodwill, Income Taxes and VIE (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2016 item	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Jul. 20, 2017 USD ($)	Dec. 31, 2016 USD ($)
Goodwill
Goodwill impairment		$ 0	$ 0	$ 0	$ 0
Income Taxes
Uncertain tax positions		0		0			$ 0
Deferred tax asset		224,804		224,804			$ 193,859
Variable Interest Entity
Carrying amount asset		15,925		15,925
Maximum exposure to loss		15,925		15,925
VIE's assets		$ 40,925		$ 40,925
Share-Based Compensation
Number of days prior to the grant that common stock and restricted stock units fair value is determined based on				3 days
JV building microwave communication networks in US and Asia
Variable Interest Entity
Number of other investors in JV \| item	9
Ownership of voting shares of JV held be each investor (as a percent)		11		11
Ownership of equity of JV held be each investor (as a percent)		11		11
JV building microwave communication networks in US and Europe
Variable Interest Entity
Ownership of voting shares (as a percent)		50.00%		50.00%
Ownership interest (as a percent)		50.00%		50.00%
KCG
Income Taxes
Unrecognized tax benefits		$ 8,000		$ 8,000
Deferred tax asset		$ 31,500		$ 31,500		$ 22,900