Subsequent Events (Details) $ in Thousands	3 Months Ended
Mar. 31, 2017 USD ($) shares	Mar. 31, 2016 USD ($) shares
Subsequent Event [Line Items]
Proceeds from Issuance or Sale of Equity	$ 21,937	$ 323,798
Common Stock [Member]
Subsequent Event [Line Items]
Stock Issued During Period, Shares, New Issues \| shares		3,828,064
Wilcon Acquisition [Member]
Subsequent Event [Line Items]
Business Acquisition, Date of Acquisition Agreement	Apr. 17, 2017
Business Combination, Consideration Transferred	$ 600,000
Fiber Miles Acquired	1,900
4.750% Senior Unsecured Notes [Member] [Member] \| Issuance of debt obligation [Member]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 350,000
Debt Instrument, Interest Rate, Stated Percentage	4.75%
Debt Instrument, Maturity Date	May 01, 2047
Debt Instrument, Issuance Date	May 01, 2017
May 2017 Equity Offering [Member] \| Sale of Stock [Domain] \| Common Stock [Member]
Subsequent Event [Line Items]
Sale of Stock, Transaction Date	May 01, 2017
Stock Issued During Period, Shares, New Issues \| shares	4,800,000
Proceeds from Issuance or Sale of Equity	$ 440,000

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Date when the business acquisition agreement was executed, in CCYY-MM-DD format.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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