Debt instrument repayment date.

No definition available.

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3291-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

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- Details

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Debt (Secured Tower Revenue Securities) (Narrative) (Details) - USD ($)							9 Months Ended
	Apr. 17, 2017	Jul. 07, 2016	Oct. 14, 2015	Oct. 15, 2014	Apr. 18, 2013	Aug. 09, 2012	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term debt							$ 8,958,801,000	$ 8,775,583,000
2010-2C Tower Securities [Member]
Debt Instrument [Line Items]
Repayments of long-term debt		$ 550,000,000
2012-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount						$ 610,000,000
Debt instrument, interest rate, stated percentage						2.933%
Repayment date of debt instrument						Dec. 11, 2017
Debt instrument, maturity date						Dec. 09, 2042	Dec. 11, 2017
Deferred financing fees	$ 2,000,000					$ 14,900,000
Repayments of long-term debt	610,000,000
Long-term debt								607,157,000
2013 Tower Securities [Member]
Debt Instrument [Line Items]
Deferred financing fees					$ 25,500,000
Debt instrument, weighted average interest rate					3.218%
Long-term debt					$ 1,330,000,000
2013-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount					$ 425,000,000
Debt instrument, interest rate, stated percentage					2.24%
Repayment date of debt instrument					Apr. 10, 2018
Debt instrument, maturity date					Apr. 09, 2043		Apr. 10, 2018
Long-term debt							$ 424,049,000	422,768,000
2013-2C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount					$ 575,000,000
Debt instrument, interest rate, stated percentage					3.722%
Repayment date of debt instrument					Apr. 11, 2023
Debt instrument, maturity date					Apr. 09, 2048		Apr. 11, 2023
Long-term debt							$ 568,339,000	567,545,000
2013-1D Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount					$ 330,000,000
Debt instrument, interest rate, stated percentage					3.598%
Repayment date of debt instrument					Apr. 10, 2018
Debt instrument, maturity date					Apr. 09, 2043		Apr. 10, 2018
Long-term debt							$ 329,240,000	328,225,000
2014 Tower Securities [Member]
Debt Instrument [Line Items]
Deferred financing fees				$ 22,500,000
Debt instrument, weighted average interest rate				3.289%
Long-term debt				$ 1,540,000,000
2014-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount				$ 920,000,000
Debt instrument, interest rate, stated percentage				2.898%
Repayment date of debt instrument				Oct. 08, 2019
Debt instrument, maturity date				Oct. 11, 2044			Oct. 08, 2019
Long-term debt							$ 914,244,000	912,219,000
2014-2C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount				$ 620,000,000
Debt instrument, interest rate, stated percentage				3.869%
Repayment date of debt instrument				Oct. 08, 2024
Debt instrument, maturity date				Oct. 08, 2049			Oct. 08, 2024
Long-term debt							$ 613,253,000	612,641,000
2015-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount			$ 500,000,000
Debt instrument, interest rate, stated percentage			3.156%
Repayment date of debt instrument			Oct. 08, 2020
Debt instrument, maturity date			Oct. 10, 2045				Oct. 08, 2020
Deferred financing fees			$ 11,200,000
Long-term debt							$ 492,920,000	491,289,000
2016-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 700,000,000
Debt instrument, interest rate, stated percentage		2.877%
Repayment date of debt instrument		Jul. 09, 2021
Debt instrument, maturity date		Jul. 10, 2046					Jul. 09, 2021
Deferred financing fees		$ 9,500,000
Long-term debt							$ 692,658,000	$ 691,322,000
2017-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 760,000,000
Debt instrument, interest rate, stated percentage	3.168%
Repayment date of debt instrument	Apr. 11, 2022
Debt instrument, maturity date	Apr. 09, 2047						Apr. 11, 2022
Deferred financing fees	$ 10,200,000
Long-term debt							$ 750,645,000
2017-1R Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 40,000,000
Debt instrument, interest rate, stated percentage	4.459%
Repayment date of debt instrument	Apr. 11, 2022
Debt instrument, maturity date	Apr. 09, 2047
2017 Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 800,000,000
Debt instrument, unused amount	$ 190,000,000