Tower Sale and Leaseback (Balance Sheet Impacts) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Tower Sale and Leaseback [Abstract]
Property and equipment	$ 21,472	$ 18,792
Tower obligation	$ 91,221	$ 87,653

The net book value of the asset(s) sold in connection with the sale of the property to another party and lease back to the seller.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 40
-Section 55
-Paragraph 52
-URI http://asc.fasb.org/extlink&oid=28365400&loc=d3e51843-112757

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 40
-Section 55
-Paragraph 50
-URI http://asc.fasb.org/extlink&oid=28365400&loc=d3e51831-112757

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 40
-Section 55
-Paragraph 51
-URI http://asc.fasb.org/extlink&oid=28365400&loc=d3e51840-112757

Name:	us-gaap_SaleLeasebackTransactionNetBookValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant