Summary of Significant Accounting Policies - Schedule of Components of Amortizable Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Amortizable intangible assets
Revenue reduction associated with amortization of permanent withdrawal fees	$ 3,664	$ 3,158
Customer Relationships
Amortizable intangible assets
Finite-Lived Intangible Assets, Gross	1,728,685		$ 1,704,105
Accumulated amortization	(427,550)		(395,278)
Net carrying amount	1,301,135		1,308,827
Customer inducements
Amortizable intangible assets
Finite-Lived Intangible Assets, Gross	57,502		140,030
Accumulated amortization	(35,149)		(66,981)
Net carrying amount	22,353		73,049
Data Center Business
Amortizable intangible assets
Finite-Lived Intangible Assets, Gross	282,609		19,314
Below Market Lease, Accumulated Amortization	349		0
Below Market Lease, Net	11,072		0
Accumulated amortization	(13,609)		(643)
Net carrying amount	269,000		18,671
Below Market Lease, Gross	11,421		0
Other finite-lived intangible assets
Amortizable intangible assets
Finite-Lived Intangible Assets, Gross	20,974		20,929
Accumulated amortization	11,936		10,728
Net carrying amount	$ 9,038		$ 10,201

Amortization of Permanent Withdrawal Fees

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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