Zayo 10-Q 10 Nov 14 2015 Q1 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	3 Months Ended
	Sep. 30, 2014	Nov. 10, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2015	'
Document Fiscal Period Focus	'Q1	'
Entity Registrant Name	'Zayo Group Holdings, Inc.	'
Entity Central Index Key	'0001608249	'
Current Fiscal Year End Date	'--06-30	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	239,008,679

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2014	Jun. 30, 2014
In Millions, unless otherwise specified
Current assets	'	'
Cash and cash equivalents	$167.30	$297.40
Trade receivables, net of allowance of $2.3 and $3.7 as of September 30, 2014 and June 30, 2014, respectively	64.5	59
Due from related parties	0.1	0.1
Prepaid expenses	28.8	25.6
Deferred income taxes, net	160.3	160.4
Other assets	2.9	2.4
Total current assets	423.9	544.9
Property and equipment, net	2,895.70	2,821.40
Intangible assets, net	735.5	709.7
Goodwill	874.3	845.3
Debt issuance costs, net	85.6	89.4
Other assets	44.7	39.7
Total assets	5,059.70	5,050.40
Current liabilities	'	'
Current portion of long-term debt	20.5	20.5
Accounts payable	28.5	27
Accrued liabilities	164.1	162.5
Accrued interest	26	57.1
Capital lease obligations, current	3.1	2.4
Deferred revenue, current	92.7	75.4
Total current liabilities	334.9	344.9
Long-term debt, non-current	3,215.50	3,219.70
Capital lease obligation, non-current	23.3	22.9
Deferred revenue, non-current	512.6	496.9
Stock-based compensation liability	514.2	392.4
Deferred income taxes, net	145.1	134.9
Other long-term liabilities	20.4	22.3
Total liabilities	4,766	4,634
Commitments and contingencies (Note 11)	'	'
Stockholder’s equity	'	'
Preferred stock, $0.001 par value--50,000,000 shares authorized; no shares issued and outstanding as of September 30, 2014 and June 30, 2014, respectively	'	'
Common Stock, $0.001 par value--850,000,000 shares authorized; 223,000,000 shares issued and outstanding as of September 30, 2014 and June 30, 2014, respectively	0.2	0.2
Additional paid-in capital	755.5	755.4
Accumulated other comprehensive income	2.1	14.4
Accumulated deficit	-442.1	-331.6
Note receivable from shareholder	-22	-22
Total stockholder’s equity	293.7	416.4
Total liabilities and stockholder’s equity	$5,059.70	$5,050.40

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Jun. 30, 2014
In Millions, except Share data, unless otherwise specified
Statement Of Financial Position [Abstract]	'	'
Trade receivables allowance	$2.30	$3.70
Preferred Stock, Par value	$0.00	$0.00
Preferred Stock, Shares Authorized	50,000,000	50,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	850,000,000	850,000,000
Common stock, shares issued	223,000,000	223,000,000
Common stock, shares outstanding	223,000,000	223,000,000

Condensed_Consolidated_Stateme

Condensed Consolidated Statements Of Operations (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]	'	'
Revenue	$320.60	$268.10
Operating costs and expenses	'	'
Operating costs (excluding depreciation and amortization)	107.3	80
Selling, general and administrative expenses	156.8	76.1
Depreciation and amortization	96	81
Total operating costs and expenses	360.1	237.1
Operating (loss)/income	-39.5	31
Other expenses	'	'
Interest expense	-46.9	-51.5
Other (loss)/income, net	-14.7	0.7
Total other expenses, net	-61.6	-50.8
Loss from operations before provision for income taxes	-101.1	-19.8
Provision for income taxes	9.4	9.3
Loss from continuing operations	-110.5	-29.1
Earnings from discontinued operations, net of income taxes	0	1.7
Net loss	($110.50)	($27.40)
Weighted-average shares used to compute net loss per share:	'	'
Basic and diluted	223	223
Loss from continuing operations per share:	'	'
Basic and diluted	($0.50)	($0.13)
Earnings from discontinued operations per share	'	'
Basic and diluted	'	$0.01
Net loss per share	'	'
Basic and diluted	($0.50)	($0.12)

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements Of Comprehensive Loss (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Comprehensive Income Net Of Tax [Abstract]	'	'
Net loss	($110.50)	($27.40)
Foreign currency translation adjustments	-12.3	-9.3
Comprehensive loss	($122.80)	($36.70)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statement of Stockholder's Equity (USD $)	Total	Common Stock [Member]	Additional paid-in Capital [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]	Accumulated Deficit [Member]	Note receivable from shareholder
In Millions, except Share data
Balance at Jun. 30, 2014	$416.40	$0.20	$755.40	$14.40	($331.60)	($22)
Balance (in shares) at Jun. 30, 2014	223,000,000	223,000,000	'	'	'	'
Stock-based compensation	0.1	'	0.1	'	'	'
Foreign currency translation adjustments	-12.3	'	'	-12.3	'	'
Net loss	-110.5	'	'	'	-110.5	'
Balance at Sep. 30, 2014	$293.70	$0.20	$755.50	$2.10	($442.10)	($22)
Balance (in shares) at Sep. 30, 2014	223,000,000	223,000,000	'	'	'	'

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities	'	'
Net loss	($110.50)	($27.40)
Earnings from discontinued operations, net of income taxes	0	-1.7
Loss from continuing operations	-110.5	-29.1
Adjustments to reconcile net loss to net cash provided by operating activities of continuing operations	'	'
Depreciation and amortization	96	81
Non-cash interest expense	2.7	6.5
Stock-based compensation	123.1	42.9
Amortization of deferred revenue	-17.3	-12.6
Additions to deferred revenue	43.2	24
Provision for bad debts	0.6	0.4
Foreign currency loss/(gain) on intercompany loans	14.7	'
Deferred income taxes	6.2	8.5
Changes in operating assets and liabilities, net of acquisitions	'	'
Trade receivables	4	7.6
Prepaid expenses	-2.1	1.6
Other assets	-5.1	-1.5
Accounts payable and accrued liabilities	-46.8	-32.8
Payables to related parties, net	'	1.7
Other liabilities	9.5	-1.1
Net cash provided by operating activities of continuing operations	118.2	97.1
Cash flows from investing activities	'	'
Purchases of property and equipment	-115.3	-86.7
Net cash used in investing activities of continuing operations	-241.8	-87
Cash flows from financing activities	'	'
Equity contributions	'	0.6
Principal payments on long-term debt	-5.1	-4.1
Principal repayments on capital lease obligations	-0.7	-0.4
Payment of debt issuance costs	'	-0.2
Net cash used in financing activities of continuing operations	-5.8	-4.1
Cash flows from continuing operations	-129.4	6
Cash flows from discontinued operations	'	'
Operating activities	'	3.3
Investing activities	'	-1.3
Financing activities	'	-1.9
Cash flows from discontinued operations	'	0.1
Effect of changes in foreign exchange rates on cash	-0.7	0.1
Net (decrease)/increase in cash and cash equivalents	-130.1	6.2
Continuing operations:	'	'
Cash and cash equivalents, beginning of year	297.4	91.3
Cash flows from continuing operations	-129.4	6
Effect of changes in foreign exchange rates on cash	-0.7	0.1
Cash and cash equivalents, end of year	167.3	97.4
Discontinued operations:	'	'
Cash and cash equivalents, beginning of year	'	16
Cash flows from discontinued operations	'	0.1
Cash and cash equivalents, end of year	'	16.1
Supplemental disclosure of non-cash investing and financing activities:	'	'
Cash paid for interest, net of capitalized interest - continuing operations	73.6	75
Cash paid for interest, net of capitalized interest - discontinued operations	0	0.1
Cash paid for income taxes	8.7	0.5
Non-cash purchases of equipment through capital leasing	1.6	3.3
(Decrease)/increase in accruals for purchases of property and equipment - continuing operations	6	-14.2
(Decrease)/increase in accruals for purchases of property and equipment - discontinued operations	'	0.1
Neo Telecoms [Member]	'	'
Cash flows from investing activities	'	'
Acquisition, net of cash acquired	-73.9	'
Colo Facilities Atlanta [Member]	'	'
Cash flows from investing activities	'	'
Acquisition, net of cash acquired	-52.5	'
Access Communications, Inc [Member]	'	'
Cash flows from investing activities	'	'
Acquisition, net of cash acquired	-0.1	'
Corelink Data Centers, LLC [Member]	'	'
Cash flows from investing activities	'	'
Acquisition, net of cash acquired	'	($0.30)

Business_and_Basis_of_Presenta

Business and Basis of Presentation	3 Months Ended
	Sep. 30, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Business and Basis of Presentation	'
	(1) BUSINESS AND BASIS OF PRESENTATION
	Business
	Zayo Group Holdings, Inc., a Delaware corporation, was formed on November 13, 2007, and is the parent company of a number of subsidiaries engaged in bandwidth infrastructure provision and services. Zayo Group Holdings, Inc. and its subsidiaries are collectively referred to as “Zayo Group Holdings” or the “Company.” The Company’s primary operating subsidiary is Zayo Group, LLC (“ZGL”). Headquartered in Boulder, Colorado, the Company operates bandwidth infrastructure assets, including fiber networks and datacenters, in the United States and Europe to offer:
	—	Physical infrastructure, including dark fiber, mobile infrastructure and colocation services.
	—	Lit services, including wavelengths, Ethernet, IP, and SONET services.
	—	Other services, provided by Zayo Professional Services and Zayo France.
	On October 22, 2014, the Company completed an initial public offering for shares of its common stock, which were listed on the New York Stock Exchange (“NYSE”) under the ticker symbol “ZAYO”. Prior to its initial public offering, Zayo Group Holdings was wholly owned by Communications Infrastructure Investments, LLC ("CII").  See Note 14 - Subsequent Events.
	Basis of Presentation
	The accompanying condensed consolidated financial statements include all the accounts of the Company and its wholly-owned subsidiaries. All inter-company accounts and transactions have been eliminated in consolidation. The accompanying condensed consolidated financial statements and related notes are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial reporting and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for quarterly reports on Form 10-Q, and do not include all of the note disclosures required by GAAP for complete financial statements. These condensed consolidated financial statements should, therefore, be read in conjunction with the consolidated financial statements and notes thereto for the year ended June 30, 2014 included in the Company’s final prospectus filed with the SEC on October 17, 2014. In the opinion of management, all adjustments considered necessary for fair presentation of financial position, results of operations and cash flows of the Company have been included herein. The results of operations for the three month periods ended September 30, 2014 are not necessarily indicative of the operating results for any future interim period or the full year.
	Unless otherwise noted, dollar amounts and disclosures throughout the notes to the condensed consolidated financial statements relate to the Company’s continuing operations and are presented in millions of dollars.
	The Company’s fiscal year ends June 30 each year, and we refer to the fiscal year ended June 30, 2014 as “Fiscal 2014” and the fiscal year ending June 30, 2015 as “Fiscal 2015.”
	Significant Accounting Policies
	There have been no changes to the Company’s significant accounting policies described in its final prospectus filed with the SEC on October 17, 2014.
	Discontinued Operations
	On June 13, 2014, the Company completed a spin-off of Onvoy, LLC and its subsidiaries (“OVS”) to CII. The spin-off is reported as an equity distribution at carryover basis equal to the net assets and liabilities of OVS on the spin-off date, as the transaction was between entities under common control. See Note 3—Spin-off of Business.
	Use of Estimates
	The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting period. Significant estimates are used when establishing allowances for doubtful accounts and accruals for disputed line cost billings, determining useful lives for depreciation and amortization and accruals for exit activities associated with real estate leases, assessing the need for impairment charges (including those related to intangible assets and goodwill), determining the fair values of assets acquired and liabilities assumed in business combinations, accounting for income taxes and related valuation allowances against deferred tax assets and estimating the common unit fair values used to compute the stock-based compensation liability. Management evaluates these estimates and judgments on an ongoing basis and makes estimates based on historical experience, current conditions, and various other assumptions that are believed to be reasonable under the circumstances. The results of these estimates form the basis for making judgments about the carrying values of assets and liabilities as well as identifying and assessing the accounting treatment with respect to commitments and contingencies. Actual results may differ from these estimates under different assumptions or conditions.
	Recently Issued Accounting Pronouncements
	On May 28, 2014, the Financial Accounting Standards Board issued Accounting Standard Update (“ASU”) 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in GAAP when it becomes effective. The new standard is effective for the Company on or after July 1, 2017. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.

Acquisitions

Acquisitions	3 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
Acquisitions	'
	(2) ACQUISITIONS
	As of September 30, 2014 and since its formation, the Company has consummated 32 transactions accounted for as business combinations. The consummation of the acquisitions was executed as part of the Company’s business strategy of expanding through acquisitions. The acquisitions of these businesses have allowed the Company to increase the scale at which it operates, which in turn affords the Company the ability to increase its operating leverage, extend its network reach, and broaden its customer base.
	The accompanying condensed consolidated financial statements include the operations of the acquired entities from their respective acquisition dates.
	Acquisitions Completed During Fiscal 2015
	Neo Telecoms (“Neo”)
	On July 1, 2014, the Company acquired a 96% equity interest in Neo, a Paris-based bandwidth infrastructure company. The purchase agreement also includes a call option to acquire the remaining 4% equity interest on or after December 31, 2015. The purchase consideration of €57.2 (or $78.1) was in consideration of acquiring 96% equity ownership in Neo and a call option to purchase the remaining 4% equity interest in Neo, and is subject to certain adjustments post-closing. The consideration consisted of cash and was paid with cash on hand from the proceeds of the Sixth Amendment to the Company’s Term Loan Facility. €8.7 (or $11.9) of the purchase consideration is currently held in escrow pending the expiration of the indemnification adjustment period. The acquisition was considered an asset purchase for tax purposes.
	Colo Facilities Atlanta (“AtlantaNAP”)
	On July 1, 2014, the Company acquired 100% of the equity interest in AtlantaNAP, a datacenter and managed services provider in Atlanta, for cash consideration of $52.5. $5.3 of the purchase price is currently held in escrow pending the expiration of the indemnification adjustment period. The acquisition was considered an asset purchase for tax purposes.
	Acquisitions Completed During Fiscal 2014
	Corelink Data Centers, LLC (“Corelink”)
	On August 1, 2013, the Company entered into an asset purchase agreement to acquire Corelink. The transaction was consummated on the same date, at which time the Company acquired substantially all of the net assets of this business for consideration of approximately $1.9, comprised of 301,949 preferred units of CII with an estimated fair value of $1.6 and cash of $0.3 net of cash acquired. The acquisition was considered a stock purchase for tax purposes. The cash consideration was paid with cash on hand.
	Access Communications, Inc. (“Access”)
	On October 1, 2013, the Company acquired 100% of the equity interest in Access, a Minnesota corporation, for cash consideration of $40.1, net of cash acquired, of which $4.0 is currently held in escrow pending the expiration of the indemnification adjustment period. The acquisition was considered a stock purchase for tax purposes. The purchase price was paid with cash on hand.
	FiberLink, LLC (“FiberLink”)
	On October 2, 2013, the Company acquired 100% of the equity interest in FiberLink, an Illinois limited liability company, for cash consideration of $43.1, which was primarily funded with available funds drawn on the Company’s revolving credit facility, the “Revolver”. The acquisition was considered an asset purchase for tax purposes.
	CoreXchange, Inc. (“CoreXchange”)
	On March 4, 2014, the Company acquired 100% of the equity interest in CoreXchange, a data center, bandwidth and managed services provider located in Dallas, Texas for consideration of $17.5, net of cash acquired. Through the transaction, the Company acquired one new data center operation located at 8600 Harry Hines Blvd. and secured additional square footage in its existing data center. The consideration was paid with cash on hand. $1.8 is currently held in escrow pending the expiration of the indemnification adjustment period. The acquisition was considered an asset purchase for tax purposes.
	Geo Networks Limited (“Geo”)
	On May 16, 2014, the Company acquired 100% of the equity interest in Ego Holdings Limited, a London-based dark fiber provider. The consideration consisted of cash of £174.3 (or $292.3), net of cash acquired, and was funded with a combination of cash on hand and available funds drawn on the Revolver. In conjunction with the acquisition, the Company repaid Geo’s existing debt obligations to the note holders totaling £113.4 and £69.1 was paid to the shareholders. The acquisition was considered an asset purchase for tax purposes.
	Acquisition Method Accounting Estimates
	The Company initially recognizes the assets and liabilities acquired from the aforementioned acquisitions based on its preliminary estimates of their acquisition date fair values. As additional information becomes known concerning the acquired assets and assumed liabilities, management may make adjustments to the opening balance sheet of the acquired company up to the end of the measurement period, which is no longer than a one year period following the acquisition date. The determination of the fair values of the acquired assets and liabilities assumed (and the related determination of estimated lives of depreciable tangible and identifiable intangible assets) requires significant judgment. As of September 30, 2014, the Company has not completed its fair value analysis and calculations in sufficient detail necessary to arrive at the final estimates of the fair value of certain working capital and non-working capital acquired assets and assumed liabilities, including the allocations to property, plant and equipment, goodwill and intangible assets, deferred revenue and resulting deferred taxes related to its acquisitions of CoreXchange, Geo, AtlantaNAP and Neo. All information presented with respect to certain working capital and non-working capital acquired assets and liabilities assumed as it relates to these acquisitions is preliminary and subject to revision pending the final fair value analysis. During the three months ended September 30, 2014, the Company finalized its fair value analysis and resulting purchase accounting for the Access and Fiberlink acquisitions consummated in Fiscal 2014.
	The table below reflects the Company's preliminary estimates of the acquisition date fair values of the assets and liabilities assumed from its Fiscal 2015 acquisitions:
		AtlantaNAP			Neo
	Acquisition date	1-Jul-14			1-Jul-14
	Cash	$	—		$	4.2
	Other current assets	0.3			13.1
	Property and equipment	9.7			42.9
	Deferred tax assets, net	0.1			—
	Intangibles	30.4			13.4
	Goodwill	13.6			25
	Other assets	—			2.4
	Total assets acquired	54.1			101
	Current liabilities	1.3			10.3
	Deferred revenue	0.3			6.3
	Deferred tax liability, net	—			6.3
	Total liabilities assumed	1.6			22.9
	Net assets acquired	52.5			78.1
	Less cash acquired	—			(4.2		)
	Net consideration paid	$	52.5		$	73.9
	The table below reflects the company's estimates of the acquisition date fair values of the assets and liabilities assumed from its Fiscal 2014 acquisitions:
		Corelink			Access			FiberLink		CoreXchange		Geo
	Acquisition date	1-Aug-13			1-Oct-13			2-Oct-13		4-Mar-14		16-May-14
	Cash	$	0.1		$	1.2		$	—	$	—	$	13.7
	Other current assets		0.5			2.3			0.8		0.7		10.7
	Property and equipment		15.9			11.5			15.9		3		219.5
	Deferred tax assets, net		—			—			7.7		0.2		—
	Intangibles		0.2			18			19.3		10.1		61.2
	Goodwill		3			24			19.8		4.7		90.2
	Other assets		0.5			—			0.1		—		9.9
	Total assets acquired		20.2			57			63.6		18.7		405.2
	Current liabilities		0.7			1			1.3		0.6		16.9
	Deferred revenue		0.2			5.1			19.2		0.4		44.3
	Capital lease obligations		14.3			—			—		0.2		—
	Deferred tax liability, net		3			9.6			—		—		38
	Total liabilities assumed		18.2			15.7			20.5		1.2		99.2
	Net assets acquired		2			41.3			43.1		17.5		306
	Less cash acquired		(0.1	)		(1.2	)		—		—		(13.7	)
	Net consideration paid	$	1.9		$	40.1		$	43.1	$	17.5	$	292.3
	The goodwill arising from the Company’s acquisitions results from synergies, anticipated incremental sales to the acquired company customer base, and economies-of-scale expected from the acquisitions. The Company has allocated the goodwill to the reporting units (in existence on the respective acquisition dates) that were expected to benefit from the acquired goodwill. The allocation was determined based on the excess of the estimated fair value of the reporting unit over the estimated fair value of the individual assets acquired and liabilities assumed that were assigned to the reporting units. Note 4 - Goodwill, discloses the preliminary and/or final allocation of the Company’s acquired goodwill to each of its reporting units.
	In each of the Company’s Fiscal 2014 and Fiscal 2015 acquisitions, the Company acquired certain customer relationships. These relationships represent a valuable intangible asset, as the Company anticipates continued business from the acquired customer bases. The Company’s estimate of the fair value of the acquired customer relationships is based on a multi-period excess earnings valuation technique that utilizes Level 3 inputs. The fair value of the acquired customer relationships for each acquisition was determined as follows: Fiscal 2015 acquisitions - AtlantaNAP, $30.4; and Neo, $13.4; Fiscal 2014 acquisitions - Access, $18.0; Fiberlink, $19.3; CoreXchange, $10.1; and Geo, $61.2. The Company has not yet finalized the valuation of acquired customer relationships for CoreXchange, Geo, AtlantaNAP and Neo. For Fiscal 2015, the Company estimated the useful life of the acquired customer relationships to be approximately 11 years for AtlantaNAP and 15 years for Neo. For Fiscal 2014, the Company estimated the useful life of the acquired customer relationships to be approximately 20 years for Access, 12 years for Corelink and Geo, 11 years for CoreXchange, and 18 years for Fiberlink.
	The previous owners of Geo had entered into various agreements, including IRU agreements with other telecommunication service providers to lease fiber and other bandwidth infrastructure in exchange for upfront cash payments. The Company accounted for acquired deferred revenue at its acquisition date fair value, which was determined utilizing the market approach. The market approach incorporated the actual up-front payments received by Geo under contracts entered within 18 months of the acquisition, as those were recent market transactions between parties unrelated to the Company. A fair value of $44.3 was assigned to the acquired deferred revenue balance of Geo. The acquired deferred revenue is being recognized over a weighted average remaining contract term of 9.7 years for Geo.
	Purchase Accounting Estimates Associated with Deferred Taxes
	Based on the Company’s fair value assessment related to deferred tax assets acquired in the Geo acquisition, a value of $38.0 was assigned to the acquired net deferred tax liabilities.
The tax effect of temporary differences that give rise to significant portions of the net deferred tax liabilities are as follows:
		Geo
		16-May-14
Deferred income tax assets:
Net operating loss carryforwards	$	2.5
Deferred revenue		4.4
Total deferred income tax assets		6.9
Deferred income tax liabilities:
Property and equipment		(32.7	)
Intangible assets		(12.2	)
Total deferred income tax liabilities		(44.9	)
Net deferred income tax assets/(liabilities)	$	(38.0	)
Adjustments to Purchase Accounting Estimates Associated with Prior Year Acquisitions
Access and Fiberlink
During the quarter ended September 30, 2014, the Company finalized its acquisition accounting for Access and Fiberlink and its previously reported allocation of the purchase consideration associated with these acquisitions as a result of changes to the original fair value estimates of certain items acquired. These changes are the result of additional information obtained since the filing of the Company's final prospectus on October 17, 2014 that related to facts and circumstances that existed at the respective acquisition dates. Related to the Access acquisition, property, plant and equipment increased by $3.1, customer relationship intangible assets increased by $2.0, and deferred tax liabilities increased by $2.0 related to the Company's final valuation of non-working capital acquired assets and the related deferred tax impacts. Related to the Fiberlink acquisition, property, plant and equipment increased by $9.9, customer relationship intangible assets increased by $2.1, and deferred tax assets increased by $0.7 related to the Company's final valuation of non-working capital acquired assets and the related deferred tax impacts. The Company has recast the previously reported consolidated balance sheet as of June 30, 2014 in connection with the finalization of acquisition accounting for these acquisitions. The Company did not recast the previously reported consolidated statement of operations for the year ended June 30, 2014 due to the immaterial effect of the related adjustments.
Transaction Costs
Transaction costs include expenses associated with professional services (i.e., legal, accounting, regulatory, etc.) rendered in connection with signed and/or closed acquisitions or disposals (including spin-offs), travel expense, severance expense incurred on the date of acquisition or disposal, and other direct expenses incurred that are associated with such acquisitions or disposals. The Company incurred transaction costs of $3.4 and $0.6 during the three months ended September 30, 2014 and 2013, respectively. Transaction costs have been included in selling, general and administrative expenses in the condensed consolidated statements of operations and in cash flows from operating activities in the condensed consolidated statements of cash flows during these periods.
Pro-forma Financial Information
The pro forma results presented below include the effects of the Company’s Fiscal 2014 acquisitions of Corelink, Access, Fiberlink, CoreXchange, and Geo and Fiscal 2015 acquisitions of the AtlantaNAP and Neo as if the acquisitions occurred on July 1, 2013. The pro forma loss for the quarters ended September 30, 2014 and 2013 includes the additional depreciation and amortization resulting from the adjustments to the value of property and equipment and intangible assets resulting from purchase accounting and adjustment to amortized revenue during Fiscal 2014 and 2015 as a result of the acquisition date valuation of assumed deferred revenue. The pro forma results also include interest expense associated with debt used to fund the acquisitions. The pro forma results do not include any anticipated synergies or other expected benefits of the acquisitions. The unaudited pro forma financial information below (in millions) is not necessarily indicative of either future results of operations or results that might have been achieved had the acquisitions been consummated as of July 1, 2013.
	Three months ended September 30,
	2014			2013
Revenue	$	320.6		$	299
Loss from operations	$	(110.5	)	$	(30.0	)
The Company is unable to determine the amount of revenue associated with each acquisition recognized in the post-acquisition period as a result of integration activities.

SpinOff_Of_Business

Spin-Off Of Business	3 Months Ended
	Sep. 30, 2014
Discontinued Operations And Disposal Groups [Abstract]	'
Spin-Off of Business	'
	-3	SPIN-OFF OF BUSINESS
	On June 13, 2014, the Company completed a spin-off of OVS, a company that provides voice and managed services. Prior to the spin-off, on March 7, 2014, OVS converted from a corporation to an LLC. At that time, certain tax attributes were retained by the Company in connection with the conversion, primarily deferred tax assets associated with net operating loss carryforwards totaling $13.7. On the spin-off date, the remaining net assets of OVS were distributed to CII.
	The spin-off is reported as an equity distribution at carryover basis equal to the net assets and liabilities of OVS on the spin-off date, as the transaction was between entities under common control.
	The Company determined that all significant cash flows and continuing involvement associated with the operations of OVS were discontinued. The results of operations of OVS are reported as discontinued operations in the accompanying consolidated financial statements for all periods presented and are presented net of intercompany eliminations.
	Earnings from discontinued operations, net of income taxes in the accompanying consolidated statements of operations are comprised of the following:
		Three months ended September 30,
		2013
	Revenues	$	20.1
	Earnings before income taxes	$	3.1
	Income tax expense		(1.4	)
	Earnings from discontinued operations, net of income taxes	$	1.7

Goodwill

Goodwill	3 Months Ended
	Sep. 30, 2014
Goodwill And Intangible Assets Disclosure [Abstract]	'
Goodwill	'
	(4) GOODWILL
	The Company’s goodwill balance was $874.3 and $845.3 as of September 30, 2014 and June 30, 2014, respectively. Additions to goodwill during the three months ended September 30, 2014 relate to the acquisitions of AtlantaNAP and Neo (see Note 2 - Acquisitions).
	The Company’s reporting units are comprised of its strategic product groups (“SPGs”): Zayo Dark Fiber (“Dark Fiber”), Zayo Wavelength Services (“Waves”), Zayo SONET Services (“SONET”), Zayo Ethernet Services (“Ethernet”), Zayo IP Services (“IP”), Zayo Mobile Infrastructure Group (“MIG”), Zayo Colocation (“zColo"), and Other (includes Zayo Professional Services ("ZPS") and Zayo France). The following rollforward reflects the allocation of goodwill acquired in the Company’s Fiscal 2014 and 2015 acquisitions to the Company’s reporting units (in millions):
		Dark Fiber			Waves			SONET		Ethernet			IP			MIG		zColo		Other		Total
	As of June 30, 2014	$	269.9		$	270		$	50.3	$	96.7		$	80.4		$	43.7	$	19.6	$	14.7	$	845.3
	Additions:
	AtlantaNAP		—			—			—		—			—			—		13.6		—		13.6
	Neo		—			—			—		—			—			—		—		23.2		23.2
	Foreign currency translation and other		(4.4	)		(3.4	)		—		(0.1	)		(0.1	)		—		0.2		—		(7.8	)
	As of September 30, 2014	$	265.5		$	266.6		$	50.3	$	96.6		$	80.3		$	43.7	$	33.4	$	37.9	$	874.3
	During the three months ended September 30, 2014, goodwill decreased by $6.7 due to foreign currency movements impacting goodwill allocated to the U.K. and France operations. In addition, the Company recorded purchase accounting adjustments to acquisitions closed during the past twelve months, which resulted in a net decrease to goodwill of $1.1 during the first quarter of Fiscal 2015. The Company did not recast the previously reported consolidated balance sheet as of June 30, 2014 and statement of operations for the year ended June 30, 2014 due to the immaterial effect of these adjustments.
	In addition, the Company has recast goodwill reported in the consolidated balance sheet as of June 30, 2014 in connection with the Company’s final valuation of property, plant and equipment and intangible assets and associated deferred taxes impact for the Access and Fiberlink acquisitions, which resulted in a net decrease to goodwill of $15.8 (see Note 2 - Acquisitions).
	Previously reported provisional allocations of goodwill to the Waves and Dark Fiber reporting units have been adjusted as of June 30, 2014 in relation to the Geo acquisition, with a corresponding increase in goodwill allocated to the Waves SPG of $27.5 and an offsetting decrease in goodwill allocated to the Dark Fiber reporting unit.

Intangible_Assets

Intangible Assets	3 Months Ended
	Sep. 30, 2014
Intangible Assets Net Excluding Goodwill [Abstract]	'
Intangible Assets	'
	(5) INTANGIBLE ASSETS
	Identifiable acquisition-related intangible assets as of September 30, 2014 and June 30, 2014 were as follows:
		Gross		Accumulated			Net
		Carrying		Amortization
		Amount
	30-Sep-14
	Finite-Lived Intangible Assets
	Customer relationships	$	825	$	(113.2	)	$	711.8
	Trade names		0.1		—			0.1
	Underlying rights		1.7		(0.1	)		1.6
			826.8		(113.3	)		713.5
	Indefinite-Lived Intangible Assets
	Certifications		3.5		—			3.5
	Underlying Rights		18.5		—			18.5
	Total	$	848.8	$	(113.3	)	$	735.5
	30-Jun-14
	Finite-Lived Intangible Assets
	Customer relationships	$	789.2	$	(104.2	)	$	685
	Trade names		0.1		—			0.1
	Underlying rights		1.8		(0.1	)		1.7
			791.1		(104.3	)		686.8
	Indefinite-Lived Intangible Assets
	Certifications		3.5		—			3.5
	Underlying rights		19.4		—			19.4
	Total	$	814	$	(104.3	)	$	709.7

LongTerm_Debt

Long-Term Debt	3 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	(6) LONG-TERM DEBT
	As of September 30, 2014 and June 30, 2014, long-term debt was as follows:
	(dollars in millions)	September 30,			June 30,
		2014			2014
	Term Loan Facility due 2019	$	2,005.70		$	2,010.80
	8.125% Senior Secured Notes due 2020		750			750
	10.125% Senior Unsecured Notes due 2020		500			500
	Total debt obligations		3,255.70			3,260.80
	Unamortized discount on Term Loan Facility		(19.7	)		(20.6	)
	due 2019
	Carrying value of debt		3,236.00			3,240.20
	Less current portion		(20.5	)		(20.5	)
	Long-term debt, less current portion	$	3,215.50		$	3,219.70
	On July 2, 2012, ZGL and Zayo Capital, Inc. (“Zayo Capital”) issued $750.0 aggregate principal amount of 8.125% senior secured first-priority notes due 2020 (the “Senior Secured Notes”) and $500.0 aggregate principal amount of 10.125% senior unsecured notes due 2020 (the “Senior Unsecured Notes”, and together with the Senior Secured Notes, the “Notes”). On July 2, 2012, ZGL also entered into a $250.0 senior secured revolving credit facility (the “Revolver”) and a senior secured term loan facility (the “Term Loan Facility”), both of which have been subsequently amended (the “Credit Agreement”). The Term Loan Facility was issued at a discount of $30.0 and has a maturity date of July 2019. The issue discount is being amortized to interest expense over the term of the loan. The terms of the amended Term Loan Facility require the Company to make quarterly principal payments of $5.1 plus an annual payment of up to 50% of excess cash flow, as determined in accordance with the Credit Agreement (no such payment was required during the three months ended September 30, 2014 and 2013, respectively).
	On November 26, 2013, ZGL and Zayo Capital entered into a Fifth Amendment (the “Fifth Amendment”) to the Company’s Credit Agreement. Under the terms of the Fifth Amendment, effective November 26, 2013, the Term Loan Facility was increased by $150.0 to $1,749.8, and the interest rate was adjusted to LIBOR plus 3.0% with a minimum LIBOR rate of 1.0%. The amended terms represented a downward adjustment of 50 basis points on the interest rate from the Fourth Amendment (the “Fourth Amendment”) to the Credit Agreement. The interest rate on the Revolver was amended to LIBOR plus 2.75% (based on the Company’s current leverage ratio), which represented a downward adjustment of 25 basis points on the interest rate from the Fourth Amendment. In connection with the Fifth Amendment, the Company did not incur a re-pricing premium.
	Also, in connection with the Fifth Amendment, the Company recognized an expense during the second quarter of Fiscal 2014 of $1.9 associated with debt extinguishment costs, including cash expense of $1.0 related to third party costs and non-cash expense of $1.0 associated with the write-off of the Company’s unamortized debt issuance costs and discount on the Term Loan Facility accounted for as an extinguishment. The Company also incurred an additional $1.5 in debt issuance costs.
	On May 16, 2014, ZGL and Zayo Capital entered into the Sixth Amendment to the Credit Agreement, which increased the Term Loan Facility by $275.0 to $2,015.9. The $275.0 add-on was priced at 99.5%, and the Company incurred debt issuance costs of $3.2. No other terms of the Credit Agreement were amended.
	The Term Loan Facility bears interest at LIBOR plus 3.0%, with a minimum LIBOR rate of 1.0%. The Revolver bears interest at LIBOR plus 2.75% (based on the Company’s current leverage ratio). Interest rates on the Term Loan Facility and Revolver as of September 30, 2014 were 4.0% and 3.0%, respectively. Interest rates on the Term Loan Facility and Revolver as of June 30, 2014 were 4.0% and 3.0%, respectively.
	As of September 30, 2014, no amounts were outstanding under the Revolver. Standby letters of credit were outstanding in the amount of $6.4 as of September 30, 2014, leaving $243.6 available under the Revolver as of September 30, 2014. The Revolver is subject to a commitment fee of 0.5% of the weighted-average unused capacity and outstanding letters of credit backed by the Revolver are subject to a 0.25% fee per annum. Outstanding letters of credit backed by the Revolver accrue interest at a rate ranging from LIBOR plus 2.0% to LIBOR plus 3.0% per annum based upon the Company’s leverage ratio. The Revolver has a maturity date of July 2017.
	Debt covenants
	The Credit Agreement, as amended, contains a covenant that requires ZGL to maintain a minimum fixed-charge coverage ratio.
	Pursuant to the Credit Agreement, ZGL shall not permit its Fixed Charge Coverage Ratio, which is defined in the Credit Agreement as the ratio of ZGL's annualized modified EBITDA (as defined in the Credit Agreement) during the most recent quarter minus Capital Expenditures (as defined in the Credit Agreement) for the twelve month period ended as of the end of each applicable fiscal quarter to interest expense for that same period, to be less than the minimum ratio for the applicable period set forth below:
	Fiscal Quarters Ending	Minimum
		Ratio
	September 30, 2014, December 31, 2014 and March 31, 2015	2.00 to 1.0
	June 30, 2015, September 30, 2015 and December 31, 2015	2.25 to 1.0
	March 31, 2016, June 30, 2016 and September 30, 2016	2.50 to 1.0
	December 31, 2016 and for each fiscal quarter thereafter	2.75 to 1.0
	ZGL was in compliance with all covenants associated with its debt agreements as of September 30, 2014.
	Debt issuance costs
	In connection with the Notes offering, Revolver and Term Loan Facility and the subsequent amendments thereto, the Company incurred debt issuance costs of $114.8 (net of extinguishments). These costs are being amortized to interest expense over the respective terms of the underlying debt instruments using the effective interest method, unless extinguished earlier, at which time the related unamortized costs are to be immediately expensed.
	The balance of debt issuance costs as of September 30, 2014 and June 30, 2014 was $85.6 and $89.4, net of accumulated amortization of $29.2 and $25.4, respectively. The amortization of debt issuance costs is included on the condensed consolidated statements of cash flows within the caption “Non-cash interest expense” along with the amortization or accretion of the premium and discount on the Company’s indebtedness and changes in the fair value of the Company’s interest rate derivatives. Interest expense associated with the amortization of debt issuance costs was $3.8 and $3.4 during the three months ended September 30, 2014 and 2013, respectively.
	Interest rate derivatives
	On August 13, 2012, the Company entered into interest rate swap agreements with an aggregate notional value of $750.0 and a maturity date of June 30, 2017. There were no up-front fees for these agreements. The contract states that the Company pays a 1.67% fixed rate of interest for the term of the agreement, beginning June 30, 2013. The counterparties pay to the Company the greater of actual LIBOR or 1.25%. The Company entered into the swap arrangements to reduce the risk of increased interest costs associated with potential changes in LIBOR rates.
	Changes in the fair value of interest rate swaps are recorded as an increase or decrease in interest expense in the consolidated statements of operations for the applicable period. During the three months ended September 30, 2014 and 2013, respectively, $(2.0) and $2.3 was recorded as an (decrease)/increase in interest expense for the change in the fair value of the interest rate swaps. The fair value of the interest rate swaps of less than $0.1 and $2.0 is included in “Other long term liabilities” in the Company’s consolidated balance sheet as of September 30, 2014 and June 30, 2014, respectively.

Income_Taxes

Income Taxes	3 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	(7) INCOME TAXES
	The Company’s provision/(benefit) for income taxes from continuing operations is summarized as follows:
		Three months ended September 30,
			2014				2013
	Current income taxes
	Federal		$	1.5			$	—
	State		0.9				0.8
	Foreign		0.8				—
	Total		3.2				0.8
	Deferred income taxes
	Federal		6.3				6.9
	State		0.2				0.2
	Foreign		(0.3		)		1.4
	Total		6.2				8.5
	Total provision for income taxes		$	9.4			$	9.3
	The United States and foreign components of income/(loss) from continuing operations before income taxes for the three months ended September 30, 2014 and 2013 are as follows:
		Three months ended September 30,
		2014				2013
	United States	$	(92.6	)		$	(24.3	)
	Foreign	(8.5		)		4.5
	Total	$	(101.1	)		$	(19.8	)
	The Company’s effective income tax rate differs from what would be expected if the federal statutory rate were applied to earnings before income taxes primarily because of certain expenses that represent permanent differences between book and tax expenses and deductions, such as stock-based compensation expense associated with the CII common units, that are recorded as an expense for financial reporting purposes but are not deductible for tax purposes.
	Reconciliations of the actual income tax provision and the tax computed by applying the U.S. federal rate to the earnings before income taxes during the three-month periods ended September 30, 2014 and 2013 are as follows:
			Three months ended September 30,
			2014				2013
	Expected benefit at statutory rate		$	(35.3	)		$	(6.9	)
	Increase due to:
	Non-deductible stock-based compensation			47.3				17
	State income taxes (benefit), net of			(4.5	)			(1.2	)
	federal benefit
	Transaction costs not deductible for tax purposes			0.2				0.2
	Foreign tax rate differential			1.1				(0.7	)
	Other, net			0.6				0.9
	Provision for income taxes		$	9.4			$	9.3
	Each interim period, management estimates the annual effective tax rate and applies that rate to its reported year-to-date earnings. The tax expense or benefit related to items for which management is unable to make reliable estimates or that are significant, unusual, or extraordinary items that will be separately reported, or reported net of their related tax effect, are individually computed and are recognized in the interim period in which those items occur. In addition, the effect of changes in enacted tax laws, tax rates or tax status is recognized in the interim period in which the change occurs.
	The computation of the annual estimated effective tax rate at each interim period requires certain estimates and significant judgments, including but not limited to the expected operating income for the year, projections of the proportion of income earned and taxed in various jurisdictions, permanent differences, and the likelihood of realizing deferred tax assets generated in both the current year and prior years. The accounting estimates used to compute the interim provision for income taxes may change as new events occur, more experience is acquired, additional information is obtained, or the tax environment changes. The effective tax rate is significantly affected by the amount of non-deductible stock-based compensation recognized during the year and given the significant assumptions inherent in the determination of this item, management is not able to reliably estimate the annual amount expected to impact the effective tax rate. As such, the tax effect of non-deductible stock-based compensation is recognized in each interim period in which the stock-based compensation is recorded.

Equity

Equity	3 Months Ended
	Sep. 30, 2014
Stockholders Equity Note [Abstract]	'
Equity	'
	(8) EQUITY
	Prior to October 16, 2014, Zayo Group Holdings was a wholly owned subsidiary of CII. See Note 14—Subsequent Events. CII was organized on November 6, 2006, and subsequently capitalized on May 7, 2007, with capital contributions from various institutional and founder investors. As of September 30, 2014 the Company was controlled by the CII board of managers, which is in turn controlled by the members of CII in accordance with the rights specified in CII’s operating agreement. At formation, 1,000 shares of common stock were issued to CII by the Company with a par value of $0.001. As discussed in Note 14—Subsequent Events, on October 9, 2014, the Company’s Board of Directors authorized a 223,000-for-one split of the Company’s common stock, that was effective upon the filing of the Company’s amended and restated certificate of incorporation on October 10, 2014. Subsequent to the stock split and prior to the Company’s initial public offering, 223,000,000 shares of common stock with a par value of $0.001 were outstanding and are retroactively reflected in the Company’s condensed consolidated financial statements and notes thereto.
	As discussed in Note 9—Stock-Based Compensation, during the quarter ended December 31, 2013, the Board of CII authorized a non-liquidating distribution to certain common unit holders of up to $10.0 and advanced $10.0 to CII, evidenced by an intercompany note receivable. During the quarter ended March 31, 2014, the board of managers of CII authorized and paid a non-liquidating distribution to the Company’s CEO for $3.0 and amended the intercompany note receivable with CII for the incremental distribution. During the quarter ended June 30, 2014, the board of managers of CII authorized and redeemed for cash the vested common units held by a member of management for $9.1 in full and final settlement of his outstanding common unit grants and further amended the intercompany note receivable with CII for the incremental distribution. The amount due from CII is reflected as a reduction of stockholder’s equity as of September 30, 2014.
	As discussed in Note 3—Spin-Off of Business, during the year ended June 30, 2014, the Company spun off OVS to CII with a corresponding non-cash distribution to CII totaling $31.8.

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Sep. 30, 2014
Share Based Compensation [Abstract]	'
Stock-Based Compensation	'
	(9) STOCK-BASED COMPENSATION
	The following table summarizes the Company’s stock-based compensation expense liability and equity classified awards included on the consolidated statements of operations.
		Three  Months Ended September 30,
		2014		2013
	Included in:
	Operating costs	$	14.4	$	3.7
	Selling, general and administrative expenses		108.7		39.2
		$	123.1	$	42.9
	Liability Classified Awards
	As of September 30, 2014, the Company has been given authorization by CII to award 625,000,000 of CII’s common units as profits interests to employees, directors, and affiliates of the Company.
	As of September 30, 2014, CII had eleven classes of common units with different liquidation preferences: Class A through Class K units. Common units are issued to employees and to independent directors of the Company and are allocated by the Chief Executive Officer and the board of managers of CII on the terms and conditions specified in the employee equity agreement. The common units do not have voting rights. At September 30, 2014, 549,268,807 common units of CII were issued and outstanding to employees, directors, and affiliates of the Company and 75,731,193 common units of CII were available to be issued. As of June 30, 2014, 552,512,338 common units of CII were issued and outstanding to employees, directors, and affiliates of the Company and 72,487,662 common units of CII were available to be issued. CII has a separate class of common units of CII issued to employees of ZPS ("ZPS Class A").  As of September 30, 2014, 18,345,417 ZPS Class A common units were issued and outstanding, and no units were available to be issued. As of June 30, 2014, 18,710,000 ZPS Class A common units were issued and outstanding, and no units were available to be issued.
	The common units are considered to be stock-based compensation with terms that require the awards to be classified as liabilities due to cash settlement features. As such, the Company accounts for the vested awards as a liability and re-measures the liability to fair value at each reporting date until the date of settlement.
	As of September 30, 2014 and June 30, 2014, the estimated fair value of the common units was as follows:
	Common Unit Class	September 30, 2014		June 30, 2014
		(estimated per unit value)
	Class A	$	2.97	$	2.47
	Class B		2.68		2.22
	Class C		2.31		1.92
	Class D		2.25		1.86
	Class E		1.95		1.62
	Class F		1.74		1.44
	Class G		0.99		0.82
	Class H		0.84		0.7
	Class I		0.54		0.45
	Class J		0.39		0.33
	Class K		0.34		0.29
	ZPS Class A		0.09		0.09
	The Company recognized stock-based compensation expense and a related increase to the stock-based compensation liability for common unit grants of $123.0 and $42.7 during the three months ended September 30, 2014 and 2013, respectively.
	The liability associated with the common units was $514.2 and $392.4 as of September 30, 2014 and June 30, 2014, respectively. As of September 30, 2014, common units with an estimated fair value of $136.5 were unvested. The fair value of the unvested common units will be recognized as stock-based compensation expense over the next three years.  See also Note 14 - Subsequent Events.
	The holders of common units of CII are not entitled to transfer their units or receive dividends or distributions, except at the discretion of CII’s board of managers. Upon a liquidation of CII, or upon a non-liquidating distribution, the holders of common units share in the proceeds after the capital contributions of the CII preferred unit holders plus their priority return of 6% per annum has been reimbursed. The remaining proceeds from a liquidation event are distributed between the preferred and common unit holders on a scale ranging from 85% to the preferred unit holders and 15% to the common unit holders to 80% to the preferred unit holders and 20% to the common unit holders. The percentage allocated to the common unit holders is dependent upon the return multiple realized by the preferred unit holders as defined in the CII operating agreement. The maximum incremental allocation of proceeds from a liquidation event to common unit holders, of 20%, occurs if the return multiple realized by a preferred unit holder reaches 3.5 times each respective preferred holder’s combined capital contributions.
	Each class of common units has a liquidation threshold. Holders of a respective class of common units begin to receive a portion of the proceeds from a liquidity event once the aggregate distributions previously made with respect to issued common units of earlier classes are equal to or greater than the liquidation threshold of the respective common unit class. Common unit holders of each of the following classes begin sharing in the proceeds of a liquidation event once the total amount distributed to earlier classes reaches the following liquidation thresholds (amounts in millions):
	Common Unit Class	Liquidation Threshold
	Class A	$	—
	Class B		15
	Class C		40
	Class D		45
	Class E		75
	Class F		95
	Class G		235
	Class H		290
	Class I		435
	Class J		515
	Class K		545
	Equity Classified Awards
	CII has issued preferred units to certain of the Company’s executives and independent directors as compensation. The terms of these preferred unit awards require the Company to record the award as an equity award. The Company estimates the fair value of these equity awards on the grant date and recognizes the related expense over the vesting period of the awards. As these awards have been issued by CII to employees and directors of the Company as compensation, the related expense has been recorded by the Company in the accompanying consolidated statements of operations. The Company recognized stock-based compensation expense and a related increase to the Company’s member’s interest account of $0.1 and $0.2 for the three months ended September 30, 2014 and 2013, respectively, including compensation recorded for preferred units granted in earlier periods.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	(10) FAIR VALUE MEASUREMENTS
	The Company’s financial instruments consist of cash and cash equivalents, restricted cash, trade receivables, accounts payable, interest rate swaps, long-term debt and stock-based compensation liability. The carrying values of cash and cash equivalents, restricted cash, trade receivables, and accounts payable approximated their fair values at September 30, 2014 and June 30, 2014 due to the short maturity of these instruments.
	The carrying value of the Company’s note obligations reflects the original amounts borrowed and was $1,250.0 as of September 30, 2014 and June 30, 2014. Based on market interest rates for debt of similar terms and average maturities, the fair value of the Company’s notes as of September 30, 2014 and June 30, 2014 was estimated to be $1,308.5 and $1,294.8, respectively. The Company’s fair value estimates associated with its note obligations were derived utilizing Level 2 inputs – quoted prices for similar instruments in active markets.
	The carrying value of the Company’s term loan obligations reflects the original amounts borrowed, net of the unamortized discount and was $1,986.0 and $1,990.2 as of September 30, 2014 and June 30, 2014, respectively. The Company’s term loan accrues interest at variable rates based upon the one month, three month or six month LIBOR (with a LIBOR floor of 1.00%) plus a spread of 3.00%. Since management does not believe that the Company’s credit quality has changed significantly since the date when the amended Term Loan Facility was entered into on May 16, 2014, its carrying amount approximates fair value. Excluding any offsetting effect of the Company’s interest rate swaps, a hypothetical increase in the applicable interest rate on the Company’s term loan of one percentage point above the 1.0% LIBOR floor would increase the Company’s annual interest expense by approximately $24.6.
	The Company’s interest rate swaps are valued using discounted cash flow techniques that use observable market inputs, such as LIBOR-based yield curves, forward rates, and credit ratings. Changes in the fair value of the interest rate swaps of $(2.0) and $2.3 were recorded as a (decrease)/increase to interest expense during the three months ended September 30, 2014 and 2013, respectively. A hypothetical increase in LIBOR rates of 100 basis points would increase the fair value of the interest rate swaps by approximately $16.5.
	The Company records its stock-based compensation liability at its estimated fair value. Financial instruments measured at fair value on a recurring basis are summarized below:
		Level	September 30,		June 30,
			2014		2014
	Liabilities Recorded at Fair Value in the Financial
	Statements:
	Interest rate swap	Level 2	$	—	$	2
	Stock-based compensation liability	Level 3	$	514.2	$	392.4

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Sep. 30, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Commitments And Contingencies	'
	(11) COMMITMENTS AND CONTINGENCIES
	Purchase commitments
	At September 30, 2014, the Company was contractually committed for $115.0 of capital expenditures for construction materials and purchases of property and equipment. A majority of these purchase commitments are expected to be satisfied in the next twelve months. These purchase commitments are primarily success based; that is, the Company has executed customer contracts that support the future capital expenditures.
	Contingencies
	In the normal course of business, the Company is party to various outstanding legal proceedings, asserted and unasserted claims, and carrier disputes. In the opinion of management, the ultimate disposition of these matters, both asserted and unasserted, will not have a material adverse effect on the Company’s financial condition, results of operations, or cash flows.

Related_Party_Transactions

Related Party Transactions	3 Months Ended
	Sep. 30, 2014
Related Party Transaction Due From To Related Party [Abstract]	'
Related Party Transactions	'
	(12) RELATED PARTY TRANSACTIONS
	The Company has ongoing contractual relationships with OVS, whereby the Company provides OVS and its subsidiaries with bandwidth capacity, and OVS provides the Company and its subsidiaries with voice services. The contractual relationships are based on agreements that were entered into at estimated market rates.
	The following table represents the revenue and expense transactions we recognized with OVS for the periods presented:
		Three Months Ended September 30,
		2014			2013
	Revenues	$	1.7		$	1.7
	Operating costs	$	(0.3	)	$	(0.4	)
	As of September 30, 2014 and June 30, 2014, the Company had a balance due from OVS in the amount of nil and $0.6, respectively.
	Dan Caruso, the Company’s Chief Executive Officer and Chairman of the Board of Directors, is a party to an aircraft charter (or membership) agreement through his affiliate, Bear Equity LLC, for business and personal travel. Under the terms of the charter agreement, all fees for the use of the aircraft are effectively variable in nature. For his business travel on behalf of the Company, Mr. Caruso is reimbursed for his use of the aircraft subject to quarterly and annual maximum reimbursement thresholds approved by the Company’s Nominating and Governance Committee. During the three months ended September 30, 2014, the Company reimbursed Mr. Caruso $0.4 for his business use of the aircraft.
	On July 2, 2012, Matthew Erickson, an officer of the Company, purchased $0.6 in aggregate principal amount of the Company’s Senior Unsecured Notes at the offering price for such notes. Mr. Erickson qualifies as an “accredited investor” (as defined in Rule 501 under the Securities Act) and purchased the notes on terms available to other investors.

Segment_Reporting

Segment Reporting	3 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segment Reporting	'
	(13) SEGMENT REPORTING
	An operating segment is a component of an entity that has all of the following characteristics:
	—	It engages in business activities from which it may earn revenues and incur expenses.
	—	Its operating results are regularly reviewed by the entity’s chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance.
	—	Its discrete financial information is available.
	The Company’s chief operating decision maker is its Chief Executive Officer.
	The Company uses the management approach to determine the segment financial information that should be disaggregated and presented separately in the Company’s notes to its financial statements. The management approach is based on the manner by which management has organized the segments within the Company for making operating decisions, allocating resources, and assessing performance. The Company evaluates performance and makes decisions about allocating resources to its operating segments based on financial measures such as revenue and adjusted EBITDA (as defined below).
	The Company’s individual strategic product groups (“SPGs”) are organized into three reportable segments based on the similarities of business activities: Physical Infrastructure, Lit Services and Other. The Physical Infrastructure reporting segment is comprised of the following SPGs: Dark Fiber, Mobile Infrastructure, and zColo. The Lit Services reporting segment is comprised of the following SPGs: Wavelengths, Ethernet, IP and SONET. SPGs report directly to the segment managers who are responsible for the operations and financial results for the Physical Infrastructure, Lit Services and Other reportable segments. The segment managers for each of the Physical Infrastructure, Lit Services and Other reportable segments report directly to the CODM, and it is the financial results of those segments that are evaluated and drive the resource allocation decisions.
	The Company’s three reportable segments are described below:
	Physical Infrastructure. Through the Physical Infrastructure segment, the Company provides raw bandwidth infrastructure to customers that require more control of their internal networks. These services include dark fiber, mobile infrastructure (fiber-to-the-tower and small cell), and colocation and interconnection. Dark fiber is a physically separate and secure, private platform for dedicated bandwidth. The Company leases dark fiber pairs (usually 2 to 12 total fibers) to its customers, who “light” the fiber using their own optronics. The Company’s mobile infrastructure services provide direct fiber connections to cell towers, small cells, hub sites, and mobile switching centers. The Company’s datacenters offer colocation and interconnection services to its customers, who then house and power the Company’s computing and networking equipment for the purpose of aggregating and distributing data, voice, Internet, and video traffic. Physical Infrastructure customers include carriers and other communication service providers, Internet service providers, wireless service providers, major media and content companies, large enterprises, and other companies that have the expertise to run their own fiber optic networks or require interconnected technical space. The contract terms in the Physical Infrastructure segment generally tend to range from three to twenty years.
	Lit Services. The Lit Services segment provides bandwidth infrastructure solutions over the Company’s metro, regional, and long-haul fiber networks where it uses optronics to light the fiber and the Company’s customers pay for access based on the amount and type of bandwidth they purchase. The Company’s lit services include wavelength, Ethernet, IP, and SONET services with capacity ranging from 1.54Mb to 100G. The Company targets customers who require a minimum of 10G of bandwidth across their networks. Lit Services customers include carriers, financial services companies, healthcare, government institutions, education institutions and other enterprises. The contract terms in this segment tend to range from two to five years.
	Other. The Other segment is primarily comprised of ZPS and Zayo France. ZPS provides network and technical resources to customers in designing, acquiring and maintaining their networks. Services are typically provided for a term of one year for a fixed recurring monthly fee in the case of network and on an hourly basis for technical resources (usage revenue). Zayo France provides services using the Company's Paris-based bandwidth infrastructure.
	Revenues for all of the Company’s products are included in one of the Company’s three reportable segments. The results of operations for each reportable segment include an allocation of certain indirect costs and corporate related costs, including overhead and third party-financed debt. The allocation is based on a percentage that represents management’s estimate of the relative burden each segment bears of indirect and corporate costs. Management has evaluated the allocation methods utilized to allocate these costs and determined they are systematic and rational. Identifiable assets for each reportable segment are reconciled to total consolidated assets including unallocated corporate assets and intersegment eliminations. Unallocated corporate assets consist primarily of cash and deferred taxes. The following tables summarize financial information of each of the segments:
	Segment Adjusted EBITDA
	Segment Adjusted EBITDA is the primary measure used by the Company’s CODM to evaluate segment operating performance.
	The Company defines Segment Adjusted EBITDA as earnings from continuing operations before interest, income taxes, depreciation and amortization (“EBITDA”) adjusted to exclude acquisition or disposal-related transaction costs, losses on extinguishment of debt, stock-based compensation, unrealized foreign currency gains on an intercompany loan, and impairment of cost method investment. The Company uses Segment Adjusted EBITDA to evaluate operating performance, and this financial measure is among the primary measures used by management for planning and forecasting of future periods. The Company believes that the presentation of Segment Adjusted EBITDA is relevant and useful for investors because it allows investors to view results in a manner similar to the method used by management and facilitates comparison of the Company’s results with the results of other companies that have different financing and capital structures.
	Segment Adjusted EBITDA results, along with other quantitative and qualitative information, are also utilized by the Company and its Compensation Committee for purposes of determining bonus payouts to employees.
	Segment Adjusted EBITDA has limitations as an analytical tool and should not be considered in isolation from, or as a substitute for, analysis of the Company’s results from operations and operating cash flows as reported under GAAP. For example, Segment Adjusted EBITDA:
	—	does not reflect capital expenditures, or future requirements for capital and major maintenance expenditures or contractual commitments;
	—	does not reflect changes in, or cash requirements for, working capital needs;
	—	does not reflect the significant interest expense, or the cash requirements necessary to service the interest payments, on the Company’s debt; and
	—	does not reflect cash required to pay income taxes.
	The Company’s computation of Segment Adjusted EBITDA may not be comparable to other similarly titled measures computed by other companies because all companies do not calculate segment Adjusted EBITDA in the same fashion.
			As of and for the three months ended September 30, 2014
			Physical				Lit Services				Other				Corp/				Total
			Infrastructure												elimination
	Revenue from external customers		$	149.7			$	156.1			$	14.8			$	—			$	320.6
	Segment Adjusted EBITDA		$	97.3			$	82.2			$	3.5			$	—			$	183
	Total assets		$	2,870.80			$	1,773.70			$	131.8			$	283.4			$	5,059.70
	Capital expenditures		$	(68.0	)		$	(46.1	)		$	(1.2	)		$	—			$	(115.3	)
			As of and for the three months ended September 30, 2013
			Physical				Lit Services				Other				Corp/				Total
			Infrastructure												elimination
	Revenue from external customers		$	113.6			$	149.4			$	5.1			$	—			$	268.1
	Segment Adjusted EBITDA		$	74.4			$	80.9			$	1.8			$	(1.5	)		$	155.6
	Capital expenditures, net of stimulus grant		$	(45.2	)		$	(41.5	)		$	—			$	—			$	(86.7	)
	reimbursements
		As of June 30, 2014
		Physical Infrastructure				Lit Services				Other				Corp/				Total
														elimination
	Total Assets	$	2,851.80			$	1,739.10			$	43.1			$	416.4			$	5,050.40
	Reconciliation from Total Segment Adjusted EBITDA to net earnings/(loss) from continuing operations
			Three months ended September 30, 2014
			2014				2013
	Segment Adjusted EBITDA		$	183			$	155.6
	Interest expense			(46.9	)			(51.5	)
	Provision for income taxes			(9.4	)			(9.3	)
	Depreciation and amortization expense			(96.0	)			(81.0	)
	Transaction costs			(3.4	)			(0.6	)
	Stock-based compensation			(123.1	)			(42.9	)
	Foreign currency loss on intercompany loans			(14.7	)			0.6
	Net (loss) from continuing operations		$	(110.5	)		$	(29.1	)

Subsequent_Events_Notes

Subsequent Events (Notes)	3 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
SUBSEQUENT EVENTS	'
	(14) SUBSEQUENT EVENTS
	Restricted Stock Grant to Chief Executive Officer
	On September 17, 2014, the Company’s Compensation Committee approved a one-time grant of restricted stock units (“RSUs”) in an amount equal to $2.8, or 144,737 RSUs, to Dan Caruso, the Company’s Chief Executive Officer. In connection with the grant, Mr. Caruso’s annual salary was reduced to 18 thousand dollars from $0.4. The grant was made on November 5, 2014. The units will vest based on the proposed new RSU vesting schedule associated with the Company’s proposed compensation plan following the Company’s initial public offering. No other terms of Mr. Caruso’s employment agreement with the Company were modified.
	Stock Split and Amended and Restated Certificate of Incorporation
	On October 9, 2014, the Board of Directors approved a 223,000-for-one stock split of the Company’s common stock. The stock split became effective upon filing of the amended and restated certificate of incorporation on October 10, 2014. Immediately subsequent to the stock split, 223,000,000 shares of common stock were outstanding. All of the shares outstanding and per share amounts have been retroactively adjusted to reflect the stock split in the accompanying condensed consolidated financial statements.
	On October 10, 2014, the Company filed its amended and restated certificate of incorporation to authorize the issuance of additional shares of common and preferred stock, establish related voting and holding rights for these shares, and address certain other matters related to corporate governance.
	Distribution of Common Stock
	On October 9, 2014, the Company and CII’s board of managers approved a non-liquidating distribution by CII of shares of the Company's common stock held by CII to holders of CII preferred and vested common units pursuant to the terms of the CII Operating Agreement. The total number of shares to be distributed to all CII preferred and common unit holders in connection with the Company's initial public offering, or upon future distributions following resolution of contingent distributions among members of CII and upon the vesting of CII common units, is fixed at 223,000,000 shares of the Company's common stock. The number of shares received by each CII preferred and common unit holder was dependent upon the actual public offering price for the offering and the class of CII units held by such preferred and common unit holders, including the applicable thresholds for distributions to the common units. Employees and independent directors of the Company with vested CII common units received shares of the Company’s common stock equal in value to the underlying value of their vested CII common units. Based on the offering price of $19.00, CII distributed 206,167,766 shares of the Company’s common stock to holders of CII preferred and common units immediately prior to the offering in respect of CII preferred and vested common units. Employees with unvested CII common units will continue to receive monthly distributions of common as they vest under the original terms of the CII common unit grant agreements in accordance with the CII operating agreement. In addition, CII will distribute additional shares of the Company’s common stock to CII preferred and common unit holders on a quarterly basis through June 30, 2016 based on stock performance.
	In connection with the distribution, the Company adjusted the corresponding stock-based compensation liability to its fair value with an offsetting adjustment to stock-based compensation expense during the second quarter of Fiscal 2015. If the Company’s stock-based compensation liability as of September 30, 2014 were derived using a value for the Company’s outstanding common shares based on $19.00 per share, the liability would be $475.7, representing a decrease of $38.5. Correspondingly, the fair value of unvested common units issued to employees and independent directors would be approximately $107.9.
	Initial Public Offering
	On October 22, 2014, the Company completed an initial public offering of 24,079,002 shares of common stock at an offering price of $19 per share. Shares sold in the offering consisted of 16,008,679 shares sold by the Company and 8,070,323 shares sold by selling stockholders (including CII investors and employees, former employees, and directors and officers of the Company). The shares sold included the exercise of an option by the underwriters to purchase an additional 3,026,371 shares from selling shareholders.  The underwriters’ option to purchase additional shares was exercised on October 20, 2014. Proceeds to the Company after deducting the underwriting discount but before other offering expenses totaled approximately $287.8, and net proceeds to selling stockholders, including the exercised underwriter option, totaled approximately $150.2. Proceeds to the Company from the offering will be recorded as an increase in common stock and additional paid-in-capital, net of direct offering costs (including previously capitalized amounts), during the second quarter of Fiscal 2015. The Company’s shares were listed on the New York Stock Exchange (NYSE) on October 17, 2014.

Business_and_Basis_of_Presenta1

Business and Basis of Presentation (Policies)	3 Months Ended
	Sep. 30, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying condensed consolidated financial statements include all the accounts of the Company and its wholly-owned subsidiaries. All inter-company accounts and transactions have been eliminated in consolidation. The accompanying condensed consolidated financial statements and related notes are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial reporting and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for quarterly reports on Form 10-Q, and do not include all of the note disclosures required by GAAP for complete financial statements. These condensed consolidated financial statements should, therefore, be read in conjunction with the consolidated financial statements and notes thereto for the year ended June 30, 2014 included in the Company’s final prospectus filed with the SEC on October 17, 2014. In the opinion of management, all adjustments considered necessary for fair presentation of financial position, results of operations and cash flows of the Company have been included herein. The results of operations for the three month periods ended September 30, 2014 are not necessarily indicative of the operating results for any future interim period or the full year.
	Unless otherwise noted, dollar amounts and disclosures throughout the notes to the condensed consolidated financial statements relate to the Company’s continuing operations and are presented in millions of dollars.
	The Company’s fiscal year ends June 30 each year, and we refer to the fiscal year ended June 30, 2014 as “Fiscal 2014” and the fiscal year ending June 30, 2015 as “Fiscal 2015.”
Significant Accounting Policies	'
	Significant Accounting Policies
	There have been no changes to the Company’s significant accounting policies described in its final prospectus filed with the SEC on October 17, 2014.
Discontinued Operations	'
	Discontinued Operations
	On June 13, 2014, the Company completed a spin-off of Onvoy, LLC and its subsidiaries (“OVS”) to CII. The spin-off is reported as an equity distribution at carryover basis equal to the net assets and liabilities of OVS on the spin-off date, as the transaction was between entities under common control. See Note 3—Spin-off of Business.
Use of Estimates	'
	Use of Estimates
	The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting period. Significant estimates are used when establishing allowances for doubtful accounts and accruals for disputed line cost billings, determining useful lives for depreciation and amortization and accruals for exit activities associated with real estate leases, assessing the need for impairment charges (including those related to intangible assets and goodwill), determining the fair values of assets acquired and liabilities assumed in business combinations, accounting for income taxes and related valuation allowances against deferred tax assets and estimating the common unit fair values used to compute the stock-based compensation liability. Management evaluates these estimates and judgments on an ongoing basis and makes estimates based on historical experience, current conditions, and various other assumptions that are believed to be reasonable under the circumstances. The results of these estimates form the basis for making judgments about the carrying values of assets and liabilities as well as identifying and assessing the accounting treatment with respect to commitments and contingencies. Actual results may differ from these estimates under different assumptions or conditions.
Recently Issued Accounting Pronouncements	'
	Recently Issued Accounting Pronouncements
	On May 28, 2014, the Financial Accounting Standards Board issued Accounting Standard Update (“ASU”) 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in GAAP when it becomes effective. The new standard is effective for the Company on or after July 1, 2017. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.

Acquisitions_Tables

Acquisitions (Tables)	3 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
Schedule of Acquisitions	'
	The table below reflects the Company's preliminary estimates of the acquisition date fair values of the assets and liabilities assumed from its Fiscal 2015 acquisitions:
		AtlantaNAP			Neo
	Acquisition date	1-Jul-14			1-Jul-14
	Cash	$	—		$	4.2
	Other current assets	0.3			13.1
	Property and equipment	9.7			42.9
	Deferred tax assets, net	0.1			—
	Intangibles	30.4			13.4
	Goodwill	13.6			25
	Other assets	—			2.4
	Total assets acquired	54.1			101
	Current liabilities	1.3			10.3
	Deferred revenue	0.3			6.3
	Deferred tax liability, net	—			6.3
	Total liabilities assumed	1.6			22.9
	Net assets acquired	52.5			78.1
	Less cash acquired	—			(4.2		)
	Net consideration paid	$	52.5		$	73.9
	The table below reflects the company's estimates of the acquisition date fair values of the assets and liabilities assumed from its Fiscal 2014 acquisitions:
		Corelink			Access			FiberLink		CoreXchange		Geo
	Acquisition date	1-Aug-13			1-Oct-13			2-Oct-13		4-Mar-14		16-May-14
	Cash	$	0.1		$	1.2		$	—	$	—	$	13.7
	Other current assets		0.5			2.3			0.8		0.7		10.7
	Property and equipment		15.9			11.5			15.9		3		219.5
	Deferred tax assets, net		—			—			7.7		0.2		—
	Intangibles		0.2			18			19.3		10.1		61.2
	Goodwill		3			24			19.8		4.7		90.2
	Other assets		0.5			—			0.1		—		9.9
	Total assets acquired		20.2			57			63.6		18.7		405.2
	Current liabilities		0.7			1			1.3		0.6		16.9
	Deferred revenue		0.2			5.1			19.2		0.4		44.3
	Capital lease obligations		14.3			—			—		0.2		—
	Deferred tax liability, net		3			9.6			—		—		38
	Total liabilities assumed		18.2			15.7			20.5		1.2		99.2
	Net assets acquired		2			41.3			43.1		17.5		306
	Less cash acquired		(0.1	)		(1.2	)		—		—		(13.7	)
	Net consideration paid	$	1.9		$	40.1		$	43.1	$	17.5	$	292.3
Schedule of Deferred Tax Assets and Liabilities	'
	The tax effect of temporary differences that give rise to significant portions of the net deferred tax liabilities are as follows:
			Geo
			16-May-14
	Deferred income tax assets:
	Net operating loss carryforwards	$	2.5
	Deferred revenue		4.4
	Total deferred income tax assets		6.9
	Deferred income tax liabilities:
	Property and equipment		(32.7	)
	Intangible assets		(12.2	)
	Total deferred income tax liabilities		(44.9	)
	Net deferred income tax assets/(liabilities)	$	(38.0	)
Schedule Of Pro-Forma Financial Information (Unaudited)	'
	The unaudited pro forma financial information below (in millions) is not necessarily indicative of either future results of operations or results that might have been achieved had the acquisitions been consummated as of July 1, 2013.
		Three months ended September 30,
		2014			2013
	Revenue	$	320.6		$	299
	Loss from operations	$	(110.5	)	$	(30.0	)
	The Company is unable to determine the amount of revenue associated with each acquisition recognized in the post-acquisition period as a result of integration activities.

SpinOff_Of_Business_Tables

Spin-Off Of Business (Tables)	3 Months Ended
	Sep. 30, 2014
Discontinued Operations And Disposal Groups [Abstract]	'
Schedule Of Earnings From Discontinued Operations	'
	Earnings from discontinued operations, net of income taxes in the accompanying consolidated statements of operations are comprised of the following:
		Three months ended September 30,
		2013
	Revenues	$	20.1
	Earnings before income taxes	$	3.1
	Income tax expense		(1.4	)
	Earnings from discontinued operations, net of income taxes	$	1.7

Goodwill_Tables

Goodwill (Tables)	3 Months Ended
	Sep. 30, 2014
Goodwill And Intangible Assets Disclosure [Abstract]	'
Schedule Of Goodwill	'
	The following rollforward reflects the allocation of goodwill acquired in the Company’s Fiscal 2014 and 2015 acquisitions to the Company’s reporting units (in millions):
		Dark Fiber			Waves			SONET		Ethernet			IP			MIG		zColo		Other		Total
	As of June 30, 2014	$	269.9		$	270		$	50.3	$	96.7		$	80.4		$	43.7	$	19.6	$	14.7	$	845.3
	Additions:
	AtlantaNAP		—			—			—		—			—			—		13.6		—		13.6
	Neo		—			—			—		—			—			—		—		23.2		23.2
	Foreign currency translation and other		(4.4	)		(3.4	)		—		(0.1	)		(0.1	)		—		0.2		—		(7.8	)
	As of September 30, 2014	$	265.5		$	266.6		$	50.3	$	96.6		$	80.3		$	43.7	$	33.4	$	37.9	$	874.3

Intangible_Assets_Tables

Intangible Assets (Tables)	3 Months Ended
	Sep. 30, 2014
Intangible Assets Net Excluding Goodwill [Abstract]	'
Schedule of Intangible Assets	'
	Identifiable acquisition-related intangible assets as of September 30, 2014 and June 30, 2014 were as follows:
		Gross		Accumulated			Net
		Carrying		Amortization
		Amount
	30-Sep-14
	Finite-Lived Intangible Assets
	Customer relationships	$	825	$	(113.2	)	$	711.8
	Trade names		0.1		—			0.1
	Underlying rights		1.7		(0.1	)		1.6
			826.8		(113.3	)		713.5
	Indefinite-Lived Intangible Assets
	Certifications		3.5		—			3.5
	Underlying Rights		18.5		—			18.5
	Total	$	848.8	$	(113.3	)	$	735.5
	30-Jun-14
	Finite-Lived Intangible Assets
	Customer relationships	$	789.2	$	(104.2	)	$	685
	Trade names		0.1		—			0.1
	Underlying rights		1.8		(0.1	)		1.7
			791.1		(104.3	)		686.8
	Indefinite-Lived Intangible Assets
	Certifications		3.5		—			3.5
	Underlying rights		19.4		—			19.4
	Total	$	814	$	(104.3	)	$	709.7

LongTerm_Debt_Tables

Long-Term Debt (Tables)	3 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Schedule of Debt	'
	As of September 30, 2014 and June 30, 2014, long-term debt was as follows:
	(dollars in millions)	September 30,			June 30,
		2014			2014
	Term Loan Facility due 2019	$	2,005.70		$	2,010.80
	8.125% Senior Secured Notes due 2020		750			750
	10.125% Senior Unsecured Notes due 2020		500			500
	Total debt obligations		3,255.70			3,260.80
	Unamortized discount on Term Loan Facility		(19.7	)		(20.6	)
	due 2019
	Carrying value of debt		3,236.00			3,240.20
	Less current portion		(20.5	)		(20.5	)
	Long-term debt, less current portion	$	3,215.50		$	3,219.70
Schedule of Fixed-Charge Coverage Ratios	'
	Pursuant to the Credit Agreement, ZGL shall not permit its Fixed Charge Coverage Ratio, which is defined in the Credit Agreement as the ratio of ZGL's annualized modified EBITDA (as defined in the Credit Agreement) during the most recent quarter minus Capital Expenditures (as defined in the Credit Agreement) for the twelve month period ended as of the end of each applicable fiscal quarter to interest expense for that same period, to be less than the minimum ratio for the applicable period set forth below:
	Fiscal Quarters Ending	Minimum
		Ratio
	September 30, 2014, December 31, 2014 and March 31, 2015	2.00 to 1.0
	June 30, 2015, September 30, 2015 and December 31, 2015	2.25 to 1.0
	March 31, 2016, June 30, 2016 and September 30, 2016	2.50 to 1.0
	December 31, 2016 and for each fiscal quarter thereafter	2.75 to 1.0

Income_Taxes_Tables

Income Taxes (Tables)	3 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Schedule of Provision for Income Taxes	'
	The Company’s provision/(benefit) for income taxes from continuing operations is summarized as follows:
		Three months ended September 30,
			2014				2013
	Current income taxes
	Federal		$	1.5			$	—
	State		0.9				0.8
	Foreign		0.8				—
	Total		3.2				0.8
	Deferred income taxes
	Federal		6.3				6.9
	State		0.2				0.2
	Foreign		(0.3		)		1.4
	Total		6.2				8.5
	Total provision for income taxes		$	9.4			$	9.3
Schedule of Income before Income Tax	'
	The United States and foreign components of income/(loss) from continuing operations before income taxes for the three months ended September 30, 2014 and 2013 are as follows:
		Three months ended September 30,
		2014				2013
	United States	$	(92.6	)		$	(24.3	)
	Foreign	(8.5		)		4.5
	Total	$	(101.1	)		$	(19.8	)
Schedule Of Reconciliation Of Income Tax Provision	'
	Reconciliations of the actual income tax provision and the tax computed by applying the U.S. federal rate to the earnings before income taxes during the three-month periods ended September 30, 2014 and 2013 are as follows:
			Three months ended September 30,
			2014				2013
	Expected benefit at statutory rate		$	(35.3	)		$	(6.9	)
	Increase due to:
	Non-deductible stock-based compensation			47.3				17
	State income taxes (benefit), net of			(4.5	)			(1.2	)
	federal benefit
	Transaction costs not deductible for tax purposes			0.2				0.2
	Foreign tax rate differential			1.1				(0.7	)
	Other, net			0.6				0.9
	Provision for income taxes		$	9.4			$	9.3

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Sep. 30, 2014
Share Based Compensation [Abstract]	'
Schedule of Employee Service Share-based Compensation Allocation of Recognized Period Costs	'
	The following table summarizes the Company’s stock-based compensation expense liability and equity classified awards included on the consolidated statements of operations.
		Three  Months Ended September 30,
		2014		2013
	Included in:
	Operating costs	$	14.4	$	3.7
	Selling, general and administrative expenses		108.7		39.2
		$	123.1	$	42.9
Schedule Of Estimated Fair Value Of Common Units	'
	As of September 30, 2014 and June 30, 2014, the estimated fair value of the common units was as follows:
	Common Unit Class	September 30, 2014		June 30, 2014
		(estimated per unit value)
	Class A	$	2.97	$	2.47
	Class B		2.68		2.22
	Class C		2.31		1.92
	Class D		2.25		1.86
	Class E		1.95		1.62
	Class F		1.74		1.44
	Class G		0.99		0.82
	Class H		0.84		0.7
	Class I		0.54		0.45
	Class J		0.39		0.33
	Class K		0.34		0.29
	ZPS Class A		0.09		0.09
Common Unit Liquidation Thresholds By Stock Series	'
	Common unit holders of each of the following classes begin sharing in the proceeds of a liquidation event once the total amount distributed to earlier classes reaches the following liquidation thresholds (amounts in millions):
	Common Unit Class	Liquidation Threshold
	Class A	$	—
	Class B		15
	Class C		40
	Class D		45
	Class E		75
	Class F		95
	Class G		235
	Class H		290
	Class I		435
	Class J		515
	Class K		545

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Schedule of Financial Instruments Measured at Fair Value on a Recurring Basis	'
	The Company records its stock-based compensation liability at its estimated fair value. Financial instruments measured at fair value on a recurring basis are summarized below:
		Level	September 30,		June 30,
			2014		2014
	Liabilities Recorded at Fair Value in the Financial
	Statements:
	Interest rate swap	Level 2	$	—	$	2
	Stock-based compensation liability	Level 3	$	514.2	$	392.4

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	3 Months Ended
	Sep. 30, 2014
Related Party Transaction Due From To Related Party [Abstract]	'
Revenue and Expense Transactions Recognized	'
	The following table represents the revenue and expense transactions we recognized with OVS for the periods presented:
		Three Months Ended September 30,
		2014			2013
	Revenues	$	1.7		$	1.7
	Operating costs	$	(0.3	)	$	(0.4	)

Segment_Reporting_Tables

Segment Reporting (Tables)	3 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Summary Of Significant Financial Information	'
	The Company’s computation of Segment Adjusted EBITDA may not be comparable to other similarly titled measures computed by other companies because all companies do not calculate segment Adjusted EBITDA in the same fashion.
			As of and for the three months ended September 30, 2014
			Physical				Lit Services				Other				Corp/				Total
			Infrastructure												elimination
	Revenue from external customers		$	149.7			$	156.1			$	14.8			$	—			$	320.6
	Segment Adjusted EBITDA		$	97.3			$	82.2			$	3.5			$	—			$	183
	Total assets		$	2,870.80			$	1,773.70			$	131.8			$	283.4			$	5,059.70
	Capital expenditures		$	(68.0	)		$	(46.1	)		$	(1.2	)		$	—			$	(115.3	)
			As of and for the three months ended September 30, 2013
			Physical				Lit Services				Other				Corp/				Total
			Infrastructure												elimination
	Revenue from external customers		$	113.6			$	149.4			$	5.1			$	—			$	268.1
	Segment Adjusted EBITDA		$	74.4			$	80.9			$	1.8			$	(1.5	)		$	155.6
	Capital expenditures, net of stimulus grant		$	(45.2	)		$	(41.5	)		$	—			$	—			$	(86.7	)
	reimbursements
		As of June 30, 2014
		Physical Infrastructure				Lit Services				Other				Corp/				Total
														elimination
	Total Assets	$	2,851.80			$	1,739.10			$	43.1			$	416.4			$	5,050.40
Reconciliation from Total Segment Adjusted EBITDA to Net Earnings/ (Loss) From Continuing Operations before Income Taxes	'
	Reconciliation from Total Segment Adjusted EBITDA to net earnings/(loss) from continuing operations
			Three months ended September 30, 2014
			2014				2013
	Segment Adjusted EBITDA		$	183			$	155.6
	Interest expense			(46.9	)			(51.5	)
	Provision for income taxes			(9.4	)			(9.3	)
	Depreciation and amortization expense			(96.0	)			(81.0	)
	Transaction costs			(3.4	)			(0.6	)
	Stock-based compensation			(123.1	)			(42.9	)
	Foreign currency loss on intercompany loans			(14.7	)			0.6
	Net (loss) from continuing operations		$	(110.5	)		$	(29.1	)

Acquisitions_Narrative_Details

Acquisitions (Narrative) (Details)

3 Months Ended

89 Months Ended

0 Months Ended

3 Months Ended

0 Months Ended

3 Months Ended

0 Months Ended

3 Months Ended

12 Months Ended

0 Months Ended

3 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

3 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

In Millions, except Share data, unless otherwise specified

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

1-May-14

1-May-14

Sep. 30, 2014

Sep. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jul. 03, 2014

Sep. 30, 2014

Jun. 30, 2014

Aug. 01, 2013

Oct. 02, 2013

Sep. 30, 2014

Jun. 30, 2014

Oct. 01, 2013

Oct. 02, 2013

Sep. 30, 2014

Mar. 04, 2014

Jun. 30, 2014

Sep. 30, 2014

Mar. 31, 2014

16-May-14

16-May-14

Sep. 30, 2014

Jun. 30, 2014

Aug. 01, 2013

Jun. 30, 2014

Oct. 02, 2013

Jun. 30, 2014

Sep. 30, 2014

USD ($)

USD ($)

business_combination

Neo Telecoms [Member]

Neo Telecoms [Member]

Neo Telecoms [Member]

Neo Telecoms [Member]

Neo Telecoms [Member]

Neo Telecoms [Member]

Neo Telecoms [Member]

Atlanta NAP [Member]

Atlanta NAP [Member]

Atlanta NAP [Member]

Colocation Acquisition [Member]

Access [Member]

Access [Member]

Access [Member]

Access [Member]

Fiberlink, LLC [Member]

Fiberlink, LLC [Member]

CoreXchange [Member]

CoreXchange [Member]

CoreXchange [Member]

CoreXchange [Member]

Geo [Member]

Geo [Member]

Geo [Member]

Geo [Member]

CoreLink [Member]

CoreLink [Member]

FiberLink [Member]

FiberLink [Member]

FiberLink [Member]

USD ($)

EUR (€)

USD ($)

USD ($)

EUR (€)

Call Option [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

GBP (£)

USD ($)

USD ($)

USD ($)

USD ($)

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of business combinations completed

'

'

32

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business acquisition, percentage of voting interests acquired

'

'

'

'

'

'

'

96.00%

96.00%

4.00%

'

'

100.00%

'

100.00%

'

'

'

100.00%

'

'

'

'

100.00%

100.00%

100.00%

'

'

'

'

'

'

'

Consideration of acquiring equity ownership

'

'

'

$78.10

€ 57.20

'

'

'

'

'

$52.50

'

'

$0.30

'

'

'

'

'

'

'

'

'

'

$292.30

£ 174.3

'

'

'

'

'

'

'

Escrow deposit

'

'

'

'

'

'

'

11.9

8.7

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase price, held in escrow

'

'

'

'

'

'

'

'

'

'

5.3

'

'

'

4

'

'

'

'

'

1.8

'

'

'

'

'

'

'

'

'

'

'

'

Net assets acquired

'

'

'

'

'

'

'

'

'

'

'

'

52.5

1.9

'

'

'

41.3

'

'

17.5

'

'

'

306

'

'

'

2

'

43.1

'

'

Business acquisition, equity interest issued or issuable, number of shares

'

'

'

'

'

'

'

'

'

'

'

'

'

301,949

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business acquisition, equity interest issued or issuable, value assigned

'

'

'

'

'

'

'

'

'

'

'

'

'

1.6

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash paid for acquisitions, net of cash acquired

'

'

'

'

'

'

73.9

'

'

'

52.5

'

'

'

40.1

'

'

'

43.1

'

17.5

'

'

'

292.3

'

'

'

1.9

'

43.1

'

'

Notes payable

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

113.4

'

'

'

'

'

'

'

Notes payable, related parties

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

69.1

'

'

'

'

'

'

'

Intangibles assumed

'

'

'

'

'

'

'

13.4

'

'

'

'

30.4

'

'

18

'

18

'

'

10.1

'

10.1

'

61.2

'

61.2

'

0.2

'

19.3

'

19.3

Estimated useful life of acquired intangible assets

'

'

'

'

'

'15 years

'

'

'

'

'

'11 years

'

'

'

'

'20 years

'

'

'

'

'11 years

'

'

'

'

'

'12 years

'

'12 years

'

'18 years

'

Deferred revenue acquired

'

'

'

'

'

'

'

'

'

'

'

'

0.3

'

'

'

'

5.1

'

'

0.4

'

'

'

44.3

'

44.3

'

0.2

'

19.2

'

'

Business combination, deferred revenue, weighted average remaining contractual term

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'9 years 8 months 12 days

'

'

'

'

'

'

Deferred Tax Assets, Net

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-38

'

38

'

'

'

'

'

'

Property plant and equipment purchase accounting adjustments

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.1

'

'

'

9.9

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite lived intangible assets, purchase accounting adjustments

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

2.1

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred tax assets purchase accounting adjustments

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

0.7

'

'

'

'

'

'

'

'

'

'

'

'

'

Acquisition related costs

$3.40

$0.60

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Acquisitions_Schedule_of_Acqui

Acquisitions (Schedule of Acquisition) (Details) (USD $)

Sep. 30, 2014

Jun. 30, 2014

Jul. 03, 2014

Jun. 30, 2014

Jul. 03, 2014

Jun. 30, 2014

Aug. 01, 2013

Oct. 02, 2013

Sep. 30, 2014

Oct. 01, 2013

Oct. 02, 2013

Sep. 30, 2014

Mar. 04, 2014

Sep. 30, 2014

16-May-14

Sep. 30, 2014

In Millions, unless otherwise specified

Atlanta NAP [Member]

Atlanta NAP [Member]

Neo [Member]

Neo [Member]

CoreLink [Member]

Access [Member]

Access [Member]

Access [Member]

FiberLink [Member]

FiberLink [Member]

CoreXchange [Member]

CoreXchange [Member]

Geo [Member]

Geo [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Acquisition date

'

'

1-Jul-14

'

1-Jul-14

'

1-Aug-13

1-Oct-13

'

'

2-Oct-13

'

4-Mar-14

'

16-May-14

'

Cash acquired

'

'

'

'

'

$4.20

$0.10

'

'

$1.20

'

'

'

'

$13.70

'

Other current assets

'

'

'

0.3

'

13.1

0.5

'

'

2.3

0.8

'

0.7

'

10.7

'

Property and equipment

'

'

'

9.7

'

42.9

15.9

'

'

11.5

15.9

'

3

'

219.5

'

Deferred tax assets, net

'

'

'

0.1

'

'

0

'

'

0

7.7

'

0.2

'

'

'

Intangibles assumed

'

'

'

30.4

'

13.4

0.2

'

18

18

19.3

19.3

10.1

10.1

61.2

61.2

Goodwill

874.3

845.3

'

13.6

'

25

3

'

'

24

19.8

'

4.7

'

90.2

'

Other assets

'

'

'

'

'

2.4

0.5

'

'

'

0.1

'

'

'

9.9

'

Total assets acquired

'

'

'

54.1

'

101

20.2

'

'

57

63.6

'

18.7

'

405.2

'

Current liabilities

'

'

'

1.3

'

10.3

0.7

'

'

1

1.3

'

0.6

'

16.9

'

Deferred revenue

'

'

'

0.3

'

6.3

0.2

'

'

5.1

19.2

'

0.4

'

44.3

44.3

Capital lease obligations

'

'

'

'

'

'

14.3

'

'

'

'

'

0.2

'

'

'

Deferred tax liability, net

'

'

'

'

'

6.3

3

'

'

9.6

'

'

'

'

38

'

Total liabilities assumed

'

'

'

1.6

'

22.9

18.2

'

'

15.7

20.5

'

1.2

'

99.2

'

Net assets acquired

'

'

'

52.5

'

78.1

2

'

'

41.3

43.1

'

17.5

'

306

'

Less cash acquired

'

'

'

'

'

-4.2

-0.1

'

'

-1.2

'

'

'

'

-13.7

'

Net cash paid

'

'

$52.50

'

$73.90

'

$1.90

$40.10

'

'

$43.10

'

$17.50

'

$292.30

'

Acquisitions_Schedule_of_Defer

Acquisitions (Schedule of Deferred Tax Assets and Liabilities) (Details) (USD $)	Jun. 13, 2014	Sep. 30, 2014	16-May-14
In Millions, unless otherwise specified		Geo [Member]	Geo [Member]
Deferred income tax assets:	'	'	'
Net operating loss carryforwards	$13.70	'	$2.50
Deferred revenue	'	'	4.4
Total deferred income tax assets	'	'	6.9
Deferred income tax liabilities:	'	'	'
Property and equipment	'	'	-32.7
Intangible assets	'	'	-12.2
Total deferred income tax liabilities	'	'	-44.9
Net deferred income tax assets/(liabilities)	'	$38	($38)

Acquisitions_Schedule_of_ProFo

Acquisitions (Schedule of Pro-Forma Financial Information) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Business Combinations [Abstract]	'	'
Revenue	$320.60	$299
Loss from operations	($110.50)	($30)

SpinOff_Of_Business_Narrative_

Spin-Off Of Business (Narrative) (Details) (USD $)	Jun. 13, 2014
In Millions, unless otherwise specified
Discontinued Operations And Disposal Groups [Abstract]	'
Net operating loss carryforwards	$13.70

SpinOff_Of_Business_Details

Spin-Off Of Business (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Discontinued Operations And Disposal Groups [Abstract]	'	'
Revenues	'	$20.10
Earnings before income taxes	'	3.1
Income tax expense	'	-1.4
Earnings from discontinued operations, net of income taxes	$0	$1.70

Goodwill_Narrative_Details

Goodwill (Narrative) (Details) (USD $)	3 Months Ended		3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2014	Jun. 30, 2014
			Access and Fiberlink,LLC [Member]	Dark Fiber [Member]
Disclosure - Goodwill (Narrative) (Details) [Line Items]	'	'	'	'
Goodwill	$874.30	$845.30	'	'
Foreign currency translation	6.7	'	'	'
Decrease to goodwill acquired	$1.10	'	$15.80	$27.50

Goodwill_Schedule_Of_Goodwill_

Goodwill (Schedule Of Goodwill) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014
Goodwill	'	$845.30
Goodwill, Other adjustments	-7.8	'
Goodwill	874.3	845.3
Atlanta NAP [Member]	'	'
Goodwill	'	13.6
Additions	13.6	'
Goodwill	'	13.6
Neo [Member]	'	'
Goodwill	'	25
Additions	23.2	'
Goodwill	'	25
Dark Fiber [Member]	'	'
Goodwill	'	269.9
Goodwill, Other adjustments	-4.4	'
Goodwill	265.5	269.9
Waves [Member]	'	'
Goodwill	'	270
Goodwill, Other adjustments	-3.4	'
Goodwill	266.6	270
SONET [Member]	'	'
Goodwill	'	50.3
Goodwill	50.3	50.3
Ethernet [Member]	'	'
Goodwill	'	96.7
Goodwill, Other adjustments	-0.1	'
Goodwill	96.6	96.7
IP [Member]	'	'
Goodwill	'	80.4
Goodwill, Other adjustments	-0.1	'
Goodwill	80.3	80.4
MIG [Member]	'	'
Goodwill	'	43.7
Goodwill	43.7	43.7
zColo [Member]	'	'
Goodwill	'	19.6
Goodwill, Other adjustments	0.2	'
Goodwill	33.4	19.6
zColo [Member] | Atlanta NAP [Member]	'	'
Additions	13.6	'
Other [Member]	'	'
Goodwill	'	14.7
Goodwill	37.9	14.7
Other [Member] | Neo [Member]	'	'
Additions	$23.20	'

Intangible_Assets_Schedule_of_

Intangible Assets (Schedule of Intangible Assets) (Details) (USD $)	Sep. 30, 2014	Jun. 30, 2014
In Millions, unless otherwise specified
Finite Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount	$826.80	$791.10
Accumulated Amortization	-113.3	-104.3
Total Net	713.5	686.8
Intangible Assets, Gross (Excluding Goodwill)	848.8	814
Intangible Assets, Net	735.5	709.7
Customer relationships [Member]	'	'
Finite Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount	825	789.2
Accumulated Amortization	-113.2	-104.2
Total Net	711.8	685
Trade names [Member]	'	'
Finite Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount	0.1	0.1
Total Net	0.1	0.1
Underlying rights [Member]	'	'
Finite Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount	1.7	1.8
Accumulated Amortization	-0.1	-0.1
Total Net	1.6	1.7
Certifications [Member]	'	'
Finite Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount, Indefinite-lived Intangibles	3.5	3.5
Easement indefinite [Member]	'	'
Finite Lived Intangible Assets [Line Items]	'	'
Gross Carrying Amount, Indefinite-lived Intangibles	$18.50	$19.40

LongTerm_Debt_Summary_of_LongT

Long-Term Debt (Summary of Long-Term Debt) (Details) (USD $)	Sep. 30, 2014	Jun. 30, 2014	16-May-14	Mar. 31, 2014
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'	'	'	'
Debt obligations	$3,255.70	$3,260.80	'	$1,749.80
Unamortized discount on Term Loan Facility due 2019	-19.7	-20.6	'	'
Carrying value of debt	3,236	3,240.20	2,015.90	'
Less current portion	-20.5	-20.5	'	'
Long-term debt, less current portion	3,215.50	3,219.70	'	'
Term Loan Facility due 2019 [Member] | Credit Facility [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Debt obligations	2,005.70	2,010.80	'	'
Secured Debt [Member] | 8.125% Senior Secured First Priority Notes due 2020 [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Debt obligations	750	750	'	'
Unsecured Debt [Member] | 10.125% Senior Unsecured Notes due 2020 [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Debt obligations	$500	$500	'	'

LongTerm_Debt_Narrative_Detail

Long-Term Debt (Narrative) (Details) (USD $)

0 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

3 Months Ended

0 Months Ended

12 Months Ended

3 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

3 Months Ended

In Millions, unless otherwise specified

16-May-14

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Jun. 30, 2014

Mar. 31, 2014

Sep. 30, 2014

Sep. 30, 2013

Jun. 30, 2014

Aug. 13, 2012

Mar. 31, 2014

16-May-14

Jul. 02, 2012

Jul. 02, 2012

Jul. 02, 2012

Jun. 30, 2014

Sep. 30, 2014

Jun. 30, 2014

Jul. 02, 2012

Sep. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Fifth Amendment [Member]

Sixth Amendment [Member]

Senior Secured Notes [Member]

Senior Unsecured Notes [Member]

Revolver [Member]

Revolver [Member]

Term Loan Facility [Member]

Term Loan Facility [Member]

Term Loan Facility [Member]

Term Loan Facility [Member]

Term Loan Facility [Member]

Term Loan Facility [Member]

Term Loan Facility [Member]

New Term Loan Facility [Member]

New Term Loan Facility [Member]

New Term Loan Facility [Member]

Original Revolver [Member]

Original Revolver [Member]

Standby Letter Of Credit [Member]

Fifth Amendment [Member]

LIBOR [Member]

LIBOR [Member]

Fourth Amendment [Member]

Fourth Amendment [Member]

Fifth Amendment [Member]

Fifth Amendment [Member]

Fifth Amendment [Member]

LIBOR [Member]

Maximum [Member]

Minimum [Member]

Minimum [Member]

Forecast [Member]

Forecast [Member]

Forecast [Member]

Third Party Costs Cash Expense [Member]

Unamortized Debt Issuance Costs And Discount On Debt [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, face amount

'

'

'

'

'

'

'

'

'

'

'

'

$750

$500

$250

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, interest rate

'

'

'

'

'

'

'

'

'

'

'

'

8.13%

10.13%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Discount on debt

'

19.7

19.7

'

20.6

'

'

'

'

'

'

'

'

'

'

'

'

'

30

'

'

'

'

'

'

'

'

'

'

Payment towards principal

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5.1

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of excess cash flows committed to debt payments

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from Issuance of Long-term Debt

'

'

'

'

'

'

'

'

'

'

150

275

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt obligations

'

3,255.70

3,255.70

'

3,260.80

1,749.80

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revolver interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.00%

'

'

'

'

'

'

'

'

'

Percentage over variable rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2.75%

'

'

'

'

1.00%

'

'

'

'

'

'

'

'

Interest rate decrease

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.25%

0.50%

'

'

'

'

'

'

Debt issuance cost

3.2

'

114.8

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.5

'

'

'

'

'

Loss on extinguishment of debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.9

1

1

'

'

'

Debt instrument carrying amount

2,015.90

3,236

3,236

'

3,240.20

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, call feature

'99.5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage over variable rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4.00%

4.00%

'

'

'

'

'

'

'

'

3.00%

3.00%

'

Outstanding letters of credit

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

'

6.4

Available borrowing capacity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

243.6

'

'

Unused commitment, percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.50%

'

0.25%

Debt instrument, maturity date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2017-07-31

'

'

Unamortized debt issuance cost

'

85.6

85.6

'

89.4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accretion of premium on debt

'

29.2

'

'

25.4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unamortized debt issuance related interest

'

'

3.8

3.4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Notional amount of derivative

'

'

'

'

'

'

'

'

'

750

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative, maturity date

'

'

'

'

'

'

30-Jun-17

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative, fixed interest rate

'

'

'

'

'

'

'

'

'

1.67%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative, floor rate

'

'

'

'

'

'

'

'

'

1.25%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Change in fair value of interest rate swap

'

'

'

'

'

'

-2

2.3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest Rate Derivative Assets, at Fair Value

'

'

'

'

'

'

$0.10

'

$2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

LongTerm_Debt_Schedule_of_Fixe

Long-Term Debt (Schedule of Fixed-Charge Coverage Ratio) (Details)	Sep. 30, 2014
Fiscal Quarter Ending September 30, 2014 [Member]	'
Schedule Of Debt Covenants [Line Items]	'
Fixed-Charge Coverage Ratio	2
Fiscal Quarter Ending December 31, 2014 [Member]	'
Schedule Of Debt Covenants [Line Items]	'
Fixed-Charge Coverage Ratio	2
Fiscal Quarter Ending March 31, 2015 [Member]	'
Schedule Of Debt Covenants [Line Items]	'
Fixed-Charge Coverage Ratio	2
Fiscal Quarter Ending June 30, 2015 [Member]	'
Schedule Of Debt Covenants [Line Items]	'
Fixed-Charge Coverage Ratio	2.25
Fiscal Quarter Ending September 30, 2015 [Member]	'
Schedule Of Debt Covenants [Line Items]	'
Fixed-Charge Coverage Ratio	2.25
Fiscal Quarter Ending December 31, 2015 [Member]	'
Schedule Of Debt Covenants [Line Items]	'
Fixed-Charge Coverage Ratio	2.25
Fiscal Quarter Ending March 31, 2016 [Member]	'
Schedule Of Debt Covenants [Line Items]	'
Fixed-Charge Coverage Ratio	2.5
Fiscal Quarter Ending June 30, 2016 [Member]	'
Schedule Of Debt Covenants [Line Items]	'
Fixed-Charge Coverage Ratio	2.5
Fiscal Quarter Ending September 30, 2016 [Member]	'
Schedule Of Debt Covenants [Line Items]	'
Fixed-Charge Coverage Ratio	2.5
Fiscal Quarter Ending December 31, 2016 and thereafter [Member]	'
Schedule Of Debt Covenants [Line Items]	'
Fixed-Charge Coverage Ratio	2.75

Income_Taxes_Schedule_Of_Provi

Income Taxes (Schedule Of Provision For Income Tax) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Current income taxes	'	'
Federal income taxes – current	$1.50	'
State income taxes – current	0.9	0.8
Foreign income taxes- current	0.8	'
Current Income Tax Expense (Benefit), Total	3.2	0.8
Deferred income taxes	'	'
Federal income taxes – deferred	6.3	6.9
State income taxes – deferred	0.2	0.2
Foreign income taxes deferred	-0.3	1.4
Deferred Income Tax Expense (Benefit), Total	6.2	8.5
Total provision for income taxes	$9.40	$9.30

Income_Taxes_IncomeLoss_from_C

Income Taxes (Income/(Loss) from Continuing Operations Before Income Tax) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'	'
United States	($92.60)	($24.30)
Foreign	-8.5	4.5
Loss from operations before provision for income taxes	($101.10)	($19.80)

Income_Taxes_Schedule_Of_Recon

Income Taxes (Schedule Of Reconciliation Of Income Tax Provision) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'	'
Expected benefit at statutory rate	($35.30)	($6.90)
Non-deductible stock-based compensation	47.3	17
State income taxes (benefit), net of federal benefit	-4.5	-1.2
Transaction costs not deductible for tax purposes	0.2	0.2
Foreign tax rate differential	1.1	-0.7
Other, net	0.6	0.9
Total provision for income taxes	$9.40	$9.30

Equity_Details

Equity (Details) (USD $)	3 Months Ended			12 Months Ended		0 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2014	Sep. 30, 2014	Oct. 09, 2014	Oct. 22, 2014	Oct. 10, 2014	Sep. 30, 2014
						Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]	CII [Member]
Deferred Compensation Arrangement With Individual Excluding Share Based Payments And Postretirement Benefits [Line Items]	'	'	'	'	'	'	'	'	'
Common stock, shares issued	223,000,000	'	'	223,000,000	223,000,000	'	16,008,679	'	1,000
Common stock, par value	$0.00	'	'	$0.00	$0.00	$19	'	$0.00	$0.00
Authorized stock split	'	'	'	'	'	'On October 9, 2014, the Board of Directors approved a 223,000-for-one stock split of the Company’s common stock.	'	'	'
Common stock, shares outstanding	223,000,000	'	'	223,000,000	223,000,000	223,000,000	'	223,000,000	'
Authorized non-liquidating cash distribution	'	'	$10	'	'	'	'	'	'
Non-liquidating distribution to common unit holders made by subsidiary to parent company	9.1	3	10	'	'	'	'	'	'
Non cash distribution to CII	'	'	'	$31.80	'	'	'	'	'

StockBased_Compensation_Summar

Stock-Based Compensation (Summary of Stock-based Compensation Expense Liability and Equity Classified Awards Included on the Consolidated Statements of Operations) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Stock - based compensation expense	$123.10	$42.90
Operating Costs [Member]	'	'
Stock - based compensation expense	14.4	3.7
Selling, General and Administrative Expenses [Member]	'	'
Stock - based compensation expense	$108.70	$39.20

StockBased_Compensation_Narrat

Stock-Based Compensation (Narrative) (Details) (USD $)

3 Months Ended

3 Months Ended

In Millions, except Share data, unless otherwise specified

Sep. 30, 2014

Sep. 30, 2013

Jun. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Jun. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Common Stock [Member]

Common Unit [Member]

Common Unit [Member]

Common Unit [Member]

Preferred Unit Holders [Member]

Preferred Unit Holders [Member]

ZPS [Member]

ZPS [Member]

CII [Member]

CII [Member]

CII [Member]

CII [Member]

CII [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Class A [Member]

Class A [Member]

Common Unit [Member]

Common Unit [Member]

Preferred Unit Holders [Member]

Maximum [Member]

Shares authorized

'

'

'

'

'

'

'

'

'

'

'

625,000,000

'

'

'

'

Common units issued

'

'

'

'

'

'

'

'

'

18,345,417

18,710,000

549,268,807

552,512,338

'

'

'

Common units outstanding

'

'

'

'

'

'

'

'

'

18,345,417

18,710,000

549,268,807

552,512,338

'

'

'

Remaining common units available for issue

'

'

'

'

'

'

'

'

'

0

0

75,731,193

72,487,662

'

'

'

Stock-based compensation

$123.10

$42.90

'

'

$123

$42.70

'

'

'

'

'

'

'

'

'

'

Stock-based compensation liability

514.2

'

392.4

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair value of unvested common units

136.5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common unit vesting period

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

Reimbursement Return

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6.00%

Proceeds from a liquidation event

'

'

'

'

'

'

15.00%

85.00%

80.00%

'

'

'

'

'

20.00%

'

Maximum incremental allocation of proceeds from a liquidation event

'

'

'

'

'

'

'

'

'

'

'

'

'

20.00%

'

'

Minimum multiple realized

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.035

Stock-based compensation related increase to member's interest

$0.10

$0.20

'

'

'

'

'

'

'

'

'

'

'

'

'

'

StockBased_Compensation_Schedu

Stock-Based Compensation (Schedule of Estimated Fair Value of Common Units) (Details) (USD $)	Sep. 30, 2014	Jun. 30, 2014
Class A [Member]	'	'
Estimated Fair Value Of Common Unit Class	$2.97	$2.47
Class A [Member] | ZPS [Member]	'	'
Estimated Fair Value Of Common Unit Class	$0.09	$0.09
Class B [Member]	'	'
Estimated Fair Value Of Common Unit Class	$2.68	$2.22
Class C [Member]	'	'
Estimated Fair Value Of Common Unit Class	$2.31	$1.92
Class D [Member]	'	'
Estimated Fair Value Of Common Unit Class	$2.25	$1.86
Class E [Member]	'	'
Estimated Fair Value Of Common Unit Class	$1.95	$1.62
Class F [Member]	'	'
Estimated Fair Value Of Common Unit Class	$1.74	$1.44
Class G [Member]	'	'
Estimated Fair Value Of Common Unit Class	$0.99	$0.82
Class H [Member]	'	'
Estimated Fair Value Of Common Unit Class	$0.84	$0.70
Class I [Member]	'	'
Estimated Fair Value Of Common Unit Class	$0.54	$0.45
Class J [Member]	'	'
Estimated Fair Value Of Common Unit Class	$0.39	$0.33
Class K [Member]	'	'
Estimated Fair Value Of Common Unit Class	$0.34	$0.29

StockBased_Compensation_Schedu1

Stock-Based Compensation (Schedule of Distributions due to a Liquidation Event) (Details) (CII [Member], USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Class A [Member]	'
Liquidation distribution to previous unit holders required to share in liquidation distribution	$0
Class B [Member]	'
Liquidation distribution to previous unit holders required to share in liquidation distribution	15
Class C [Member]	'
Liquidation distribution to previous unit holders required to share in liquidation distribution	40
Class D [Member]	'
Liquidation distribution to previous unit holders required to share in liquidation distribution	45
Class E [Member]	'
Liquidation distribution to previous unit holders required to share in liquidation distribution	75
Class F [Member]	'
Liquidation distribution to previous unit holders required to share in liquidation distribution	95
Class G [Member]	'
Liquidation distribution to previous unit holders required to share in liquidation distribution	235
Class H [Member]	'
Liquidation distribution to previous unit holders required to share in liquidation distribution	290
Class I [Member]	'
Liquidation distribution to previous unit holders required to share in liquidation distribution	435
Class J [Member]	'
Liquidation distribution to previous unit holders required to share in liquidation distribution	515
Class K [Member]	'
Liquidation distribution to previous unit holders required to share in liquidation distribution	$545

Fair_Value_Measurements_Narrat

Fair Value Measurements (Narrative) (Details) (USD $)	3 Months Ended			3 Months Ended				3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2014	Jun. 30, 2014
				Interest Rate Swap [Member]	Interest Rate Swap [Member]	Notes [Member]	Notes [Member]	Term Loan Facility [Member]	Term Loan Facility [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]	'	'	'	'	'	'	'	'	'
Carrying value of the notes	$3,255.70	$3,260.80	$1,749.80	'	'	$1,250	$1,250	$1,986	$1,990.20
Fair value of the notes	'	'	'	'	'	1,308.50	1,294.80	'	'
Floor rate	'	'	'	'	'	'	'	1.00%	'
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum	'	'	'	'	'	'	'	3.00%	'
Hypothetical interest rate increase	'	'	'	1.00%	'	'	'	1.00%	'
Hypothetical annual interest expense	24.6	'	'	'	'	'	'	'	'
Change in fair value of interest rate swap	'	'	'	-2	2.3	'	'	'	'
Hypothetical increase to interest rate swap fair value	$16.50	'	'	'	'	'	'	'	'

Fair_Value_Measurements_Schedu

Fair Value Measurements (Schedule Of Financial Instruments Measured At Fair Value On A Recurring Basis) (Details) (USD $)	Sep. 30, 2014	Jun. 30, 2014
In Millions, unless otherwise specified
Level 2 [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Interest Rate Derivative Liabilities, at Fair Value	'	$2
Level 3 [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Stock-based compensation liability	$514.20	$392.40

Commitments_and_Contingencies_

Commitments and Contingencies (Narrative) (Details) (USD $)	Sep. 30, 2014
In Millions, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]	'
Purchase commitments	$115

Related_Party_Transactions_Sch

Related Party Transactions (Schedule of Transactions Recognized ) (Details) (OVS [Member], USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
OVS [Member]	'	'
Related Party Transaction [Line Items]	'	'
Revenues	$1.70	$1.70
Operating costs	($0.30)	($0.40)

Related_Party_Transactions_Nar

Related Party Transactions (Narrative) (Details) (USD $)	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2014	Jul. 02, 2012
In Millions, unless otherwise specified			OVS [Member]	OVS [Member]	Dan Caruso [Member]	Matthew Erickson [Member]
					Aircraft Reimbursement [Member]
Related Party Transaction [Line Items]	'	'	'	'	'	'
Due from related parties	$0.10	$0.10	$0	$0.60	'	'
Payable to related party settled	'	'	'	'	0.4	'
Purchase price of notes	'	'	'	'	'	$0.60

Segment_Reporting_Narrative_De

Segment Reporting (Narrative) (Details)	3 Months Ended
	Sep. 30, 2014
	segments
Segment Reporting Information [Line Items]	'
Contract term	'1 year
Number of reportable segments	3
Physical Infrastructure [Member] | Minimum [Member]	'
Segment Reporting Information [Line Items]	'
Contract term	'3 years
Physical Infrastructure [Member] | Maximum [Member]	'
Segment Reporting Information [Line Items]	'
Contract term	'20 years
Lit Services [Member] | Minimum [Member]	'
Segment Reporting Information [Line Items]	'
Contract term	'2 years
Lit Services [Member] | Maximum [Member]	'
Segment Reporting Information [Line Items]	'
Contract term	'5 years

Segment_Reporting_Summary_of_S

Segment Reporting (Summary of Significant Financial Information) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014
Segment Reporting Information [Line Items]	'	'	'
Revenue from external customers	$320.60	$268.10	'
Segment Adjusted EBITDA	183	155.6	'
Total assets	5,059.70	'	5,050.40
Capital expenditures	-115.3	-86.7	'
Interest expense	-46.9	-51.5	'
Provision for income taxes	-9.4	-9.3	'
Depreciation and amortization expense	-96	-81	'
Transaction costs	-3.4	-0.6	'
Stock-based compensation	-123.1	-42.9	'
Foreign currency loss on intercompany loans	-14.7	0.6	'
Loss from continuing operations	-110.5	-29.1	'
Reportable Segments [Member] | Physical Infrastructure [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Revenue from external customers	149.7	113.6	'
Segment Adjusted EBITDA	97.3	74.4	'
Total assets	2,870.80	'	2,851.80
Capital expenditures	-68	-45.2	'
Reportable Segments [Member] | Lit Services [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Revenue from external customers	156.1	149.4	'
Segment Adjusted EBITDA	82.2	80.9	'
Total assets	1,773.70	'	1,739.10
Capital expenditures	-46.1	-41.5	'
Reportable Segments [Member] | Other [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Revenue from external customers	14.8	5.1	'
Segment Adjusted EBITDA	3.5	1.8	'
Total assets	131.8	'	43.1
Capital expenditures	-1.2	'	'
Corporate/eliminations [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Segment Adjusted EBITDA	'	-1.5	'
Total assets	$283.40	'	$416.40

Subsequent_Events_Details

Subsequent Events (Details) (USD $)

3 Months Ended

0 Months Ended

0 Months Ended

Sep. 30, 2014

Jun. 30, 2014

Oct. 20, 2014

Oct. 09, 2014

Oct. 22, 2014

Oct. 10, 2014

Oct. 22, 2014

Oct. 22, 2014

Oct. 09, 2014

Sep. 17, 2014

Sep. 16, 2014

Sep. 17, 2014

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

restricted stock units (“RSUs”)

Chief Executive Officer

Chief Executive Officer

Initial Public Offering [Member]

Employee Stock [Member]

CII [Member]

Subsequent Event [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Restricted stock units granted

'

'

'

'

'

'

'

'

'

$2,800,000

'

'

Restricted stock units granted

'

'

'

'

'

'

'

'

'

144,737

'

'

Reduction in annual salaries

'

'

'

'

'

'

'

'

'

'

400,000

18,000

Authorized stock split

'

'

'

'On October 9, 2014, the Board of Directors approved a 223,000-for-one stock split of the Company’s common stock.

'

'

'

'

'

'

'

'

Common stock, shares outstanding

223,000,000

223,000,000

'

223,000,000

'

223,000,000

'

'

'

'

'

'

Common stock, par value

$0.00

$0.00

'

$19

'

$0.00

'

'

'

'

'

'

Number of shares distributed to stock holders

'

'

'

'

'

'

'

'

206,167,766

'

'

'

Stock-based compensation expense

107,900,000

'

'

'

'

'

'

'

'

'

'

'

Stock-based compensation liability

'

'

'

475,700,000

'

'

'

'

'

'

'

'

Increase (decrease) in share based compensation

'

'

'

38,500,000

'

'

'

'

'

'

'

'

Common stock, shares issued

223,000,000

223,000,000

'

'

16,008,679

'

24,079,002

8,070,323

'

'

'

'

Price per share

'

'

'

'

'

'

$19

'

'

'

'

'

Stock option exercised

'

'

3,026,371

'

'

'

'

'

'

'

'

'

Proceeds from initial public offering before other expenses

'

'

287,800,000

'

'

'

'

'

'

'

'

'

Net proceeds from initial public offering including underwriter options

'

'

$150,200,000

'

'

'

'

'

'

'

'

'