Segments (Narrative) (Details)	3 Months Ended
Mar. 31, 2016
Fiber optic cable systems [Member]
Segment Reporting Information [Line Items]
Percentage of long-lived assets not in USA	82.00%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration