Segment Reporting (Tables)

3 Months Ended

Sep. 30, 2016

Segment Reporting [Abstract]

Summary of Financial Information by Segments

	As of and for the three months ended September 30, 2016
	Dark Fiber Solutions		Network Connectivity		Colocation and Cloud Infrastructure		Zayo Canada		Other		Corp/ Eliminations		Total
	(in millions)
Revenue from external customers	$	148.4	$	175.6	$	64.1	$	112.2	$	4.6	$	—	$	504.9
Segment Adjusted EBITDA		108.2		91.6		32.2		27.5		1.1		—		260.6
Total assets		3,237.8		1,898.1		1,090.5		475.7		32.3		99.6		6,834.0
Capital expenditures		128.1		48.9		28.0		3.3		—		—		208.3

	As of and for the three months ended September 30, 2015
	Dark Fiber Solutions		Network Connectivity		Colocation and Cloud Infrastructure		Zayo Canada		Other		Corp/ Eliminations		Total
	(in millions)
Revenue from external customers	$	135.0	$	167.0	$	58.3	$	—	$	6.5	$	—	$	366.8
Segment Adjusted EBITDA		96.6		88.7		28.4		—		1.7		—		215.4
Total assets		2,862.9		1,825.5		1,022.1		—		36.3		419.1		6,165.9
Capital expenditures		93.5		46.7		19.0		—		—		—		159.2

	As of June 30, 2016
	Dark Fiber Solutions		Network Connectivity		Colocation and Cloud Infrastructure		Zayo Canada		Other		Corp/ Eliminations		Total
	(in millions)
Total assets	$	3,155.0	$	1,901.8	$	1,069.4	$	477.6	$	33.4	$	90.3	$	6,727.5

Reconciliation from Total Segment Adjusted EBITDA to income/(loss) from operations before taxes

	For the three months ended September 30,
	2016		2015
	(in millions)
Total Segment Adjusted EBITDA	$	260.6	$	215.4
Interest expense		(53.3)		(53.8)
Depreciation and amortization expense		(138.5)		(117.1)
Transaction costs		(3.0)		—
Stock-based compensation		(32.0)		(46.1)
Foreign currency loss on intercompany loans		(11.2)		(10.7)
Non-cash loss on investments		(0.3)		(0.2)
Income/(loss) from operations before income taxes	$	22.3	$	(12.5)