Condensed Consolidating Financial Information -Condensed Balance Sheets (Details) - USD ($) $ in Millions |
Dec. 31, 2019 |
Jan. 01, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Condensed Balance Sheet Statements, Captions [Line Items] |
|
|
|
|
|
Cash and cash equivalents |
$ 59.1
|
|
$ 52.7
|
$ 48.3
|
|
Receivables, less allowances |
290.0
|
|
264.9
|
|
|
Other current assets |
86.7
|
|
111.9
|
|
|
Total current assets |
435.8
|
|
429.5
|
|
|
Property and equipment, net |
666.2
|
|
652.9
|
|
|
Goodwill |
2,083.1
|
|
2,079.7
|
2,128.0
|
|
Intangible assets |
550.9
|
|
537.2
|
|
|
Operating lease assets |
1,457.0
|
$ 1,200.0
|
0.0
|
|
|
Investments in subsidiaries |
0.0
|
|
0.0
|
|
|
Prepaid MTA equipment deployment costs |
116.1
|
|
60.6
|
|
|
Other assets |
73.2
|
|
68.8
|
|
|
Intercompany |
0.0
|
|
0.0
|
|
|
Total assets |
5,382.3
|
|
3,828.7
|
3,808.2
|
|
Total current liabilities |
650.0
|
|
402.6
|
|
|
Long-term debt, net |
2,222.1
|
|
2,149.6
|
|
|
Deferred income tax liabilities, net |
18.0
|
|
17.0
|
|
|
Asset retirement obligation |
35.1
|
|
34.2
|
34.7
|
|
Operating lease liabilities |
1,285.1
|
|
0.0
|
|
|
Deficit In excess of investment in subsidiaries |
0.0
|
|
0.0
|
|
|
Other liabilities |
45.6
|
|
80.0
|
|
|
Intercompany |
0.0
|
|
0.0
|
|
|
Total liabilities |
4,255.9
|
|
2,683.4
|
|
|
Total stockholders’ equity |
1,093.8
|
|
1,102.8
|
1,181.1
|
$ 1,232.9
|
Non-controlling interests |
32.6
|
|
42.5
|
|
|
Total equity |
1,126.4
|
|
1,145.3
|
$ 1,226.6
|
$ 1,233.0
|
Total liabilities and equity |
5,382.3
|
|
3,828.7
|
|
|
Parent Company |
|
|
|
|
|
Condensed Balance Sheet Statements, Captions [Line Items] |
|
|
|
|
|
Cash and cash equivalents |
0.0
|
|
0.0
|
|
|
Receivables, less allowances |
0.0
|
|
0.0
|
|
|
Other current assets |
0.0
|
|
0.0
|
|
|
Total current assets |
0.0
|
|
0.0
|
|
|
Property and equipment, net |
0.0
|
|
0.0
|
|
|
Goodwill |
0.0
|
|
0.0
|
|
|
Intangible assets |
0.0
|
|
0.0
|
|
|
Operating lease assets |
0.0
|
|
|
|
|
Investments in subsidiaries |
1,093.8
|
|
1,102.8
|
|
|
Prepaid MTA equipment deployment costs |
0.0
|
|
0.0
|
|
|
Other assets |
0.0
|
|
0.0
|
|
|
Intercompany |
0.0
|
|
0.0
|
|
|
Total assets |
1,093.8
|
|
1,102.8
|
|
|
Total current liabilities |
0.0
|
|
0.0
|
|
|
Long-term debt, net |
0.0
|
|
0.0
|
|
|
Deferred income tax liabilities, net |
0.0
|
|
0.0
|
|
|
Asset retirement obligation |
0.0
|
|
0.0
|
|
|
Operating lease liabilities |
0.0
|
|
|
|
|
Deficit In excess of investment in subsidiaries |
0.0
|
|
0.0
|
|
|
Other liabilities |
0.0
|
|
0.0
|
|
|
Intercompany |
0.0
|
|
0.0
|
|
|
Total liabilities |
0.0
|
|
0.0
|
|
|
Total stockholders’ equity |
1,093.8
|
|
1,102.8
|
|
|
Non-controlling interests |
0.0
|
|
0.0
|
|
|
Total equity |
1,093.8
|
|
1,102.8
|
|
|
Total liabilities and equity |
1,093.8
|
|
1,102.8
|
|
|
Subsidiary Issuer |
|
|
|
|
|
Condensed Balance Sheet Statements, Captions [Line Items] |
|
|
|
|
|
Cash and cash equivalents |
12.7
|
|
12.0
|
|
|
Receivables, less allowances |
0.0
|
|
0.0
|
|
|
Other current assets |
1.0
|
|
1.0
|
|
|
Total current assets |
13.7
|
|
13.0
|
|
|
Property and equipment, net |
0.0
|
|
0.0
|
|
|
Goodwill |
0.0
|
|
0.0
|
|
|
Intangible assets |
0.0
|
|
0.0
|
|
|
Operating lease assets |
0.0
|
|
|
|
|
Investments in subsidiaries |
3,330.0
|
|
3,257.5
|
|
|
Prepaid MTA equipment deployment costs |
0.0
|
|
0.0
|
|
|
Other assets |
3.5
|
|
2.3
|
|
|
Intercompany |
0.0
|
|
0.0
|
|
|
Total assets |
3,347.2
|
|
3,272.8
|
|
|
Total current liabilities |
26.7
|
|
18.0
|
|
|
Long-term debt, net |
2,222.1
|
|
2,149.6
|
|
|
Deferred income tax liabilities, net |
0.0
|
|
0.0
|
|
|
Asset retirement obligation |
0.0
|
|
0.0
|
|
|
Operating lease liabilities |
0.0
|
|
|
|
|
Deficit In excess of investment in subsidiaries |
0.0
|
|
0.0
|
|
|
Other liabilities |
4.6
|
|
2.4
|
|
|
Intercompany |
0.0
|
|
0.0
|
|
|
Total liabilities |
2,253.4
|
|
2,170.0
|
|
|
Total stockholders’ equity |
1,093.8
|
|
1,102.8
|
|
|
Non-controlling interests |
0.0
|
|
0.0
|
|
|
Total equity |
1,093.8
|
|
1,102.8
|
|
|
Total liabilities and equity |
3,347.2
|
|
3,272.8
|
|
|
Guarantor Subsidiaries |
|
|
|
|
|
Condensed Balance Sheet Statements, Captions [Line Items] |
|
|
|
|
|
Cash and cash equivalents |
1.1
|
|
0.0
|
|
|
Receivables, less allowances |
0.0
|
|
52.7
|
|
|
Other current assets |
169.7
|
|
176.3
|
|
|
Total current assets |
170.8
|
|
229.0
|
|
|
Property and equipment, net |
618.2
|
|
604.3
|
|
|
Goodwill |
2,059.9
|
|
2,059.9
|
|
|
Intangible assets |
479.5
|
|
478.4
|
|
|
Operating lease assets |
1,344.3
|
|
|
|
|
Investments in subsidiaries |
331.6
|
|
261.9
|
|
|
Prepaid MTA equipment deployment costs |
116.1
|
|
60.6
|
|
|
Other assets |
65.8
|
|
63.4
|
|
|
Intercompany |
77.5
|
|
81.0
|
|
|
Total assets |
5,263.7
|
|
3,838.5
|
|
|
Total current liabilities |
590.5
|
|
375.5
|
|
|
Long-term debt, net |
0.0
|
|
0.0
|
|
|
Deferred income tax liabilities, net |
0.0
|
|
0.0
|
|
|
Asset retirement obligation |
30.6
|
|
29.9
|
|
|
Operating lease liabilities |
1,188.0
|
|
|
|
|
Deficit In excess of investment in subsidiaries |
2,236.2
|
|
2,154.7
|
|
|
Other liabilities |
37.0
|
|
74.9
|
|
|
Intercompany |
87.6
|
|
100.7
|
|
|
Total liabilities |
4,169.9
|
|
2,735.7
|
|
|
Total stockholders’ equity |
1,093.8
|
|
1,102.8
|
|
|
Non-controlling interests |
0.0
|
|
0.0
|
|
|
Total equity |
1,093.8
|
|
1,102.8
|
|
|
Total liabilities and equity |
5,263.7
|
|
3,838.5
|
|
|
Non-Guarantor Subsidiaries |
|
|
|
|
|
Condensed Balance Sheet Statements, Captions [Line Items] |
|
|
|
|
|
Cash and cash equivalents |
45.3
|
|
40.7
|
|
|
Receivables, less allowances |
320.8
|
|
232.1
|
|
|
Other current assets |
76.9
|
|
81.5
|
|
|
Total current assets |
443.0
|
|
354.3
|
|
|
Property and equipment, net |
48.0
|
|
48.6
|
|
|
Goodwill |
23.2
|
|
19.8
|
|
|
Intangible assets |
71.4
|
|
58.8
|
|
|
Operating lease assets |
112.7
|
|
|
|
|
Investments in subsidiaries |
0.0
|
|
0.0
|
|
|
Prepaid MTA equipment deployment costs |
0.0
|
|
0.0
|
|
|
Other assets |
3.9
|
|
3.1
|
|
|
Intercompany |
87.6
|
|
100.7
|
|
|
Total assets |
789.8
|
|
585.3
|
|
|
Total current liabilities |
224.5
|
|
175.9
|
|
|
Long-term debt, net |
0.0
|
|
0.0
|
|
|
Deferred income tax liabilities, net |
18.0
|
|
17.0
|
|
|
Asset retirement obligation |
4.5
|
|
4.3
|
|
|
Operating lease liabilities |
97.1
|
|
|
|
|
Deficit In excess of investment in subsidiaries |
0.0
|
|
0.0
|
|
|
Other liabilities |
4.0
|
|
2.7
|
|
|
Intercompany |
77.5
|
|
81.0
|
|
|
Total liabilities |
425.6
|
|
280.9
|
|
|
Total stockholders’ equity |
331.6
|
|
261.9
|
|
|
Non-controlling interests |
32.6
|
|
42.5
|
|
|
Total equity |
364.2
|
|
304.4
|
|
|
Total liabilities and equity |
789.8
|
|
585.3
|
|
|
Eliminations |
|
|
|
|
|
Condensed Balance Sheet Statements, Captions [Line Items] |
|
|
|
|
|
Cash and cash equivalents |
0.0
|
|
0.0
|
|
|
Receivables, less allowances |
(30.8)
|
|
(19.9)
|
|
|
Other current assets |
(160.9)
|
|
(146.9)
|
|
|
Total current assets |
(191.7)
|
|
(166.8)
|
|
|
Property and equipment, net |
0.0
|
|
0.0
|
|
|
Goodwill |
0.0
|
|
0.0
|
|
|
Intangible assets |
0.0
|
|
0.0
|
|
|
Operating lease assets |
0.0
|
|
|
|
|
Investments in subsidiaries |
(4,755.4)
|
|
(4,622.2)
|
|
|
Prepaid MTA equipment deployment costs |
0.0
|
|
0.0
|
|
|
Other assets |
0.0
|
|
0.0
|
|
|
Intercompany |
(165.1)
|
|
(181.7)
|
|
|
Total assets |
(5,112.2)
|
|
(4,970.7)
|
|
|
Total current liabilities |
(191.7)
|
|
(166.8)
|
|
|
Long-term debt, net |
0.0
|
|
0.0
|
|
|
Deferred income tax liabilities, net |
0.0
|
|
0.0
|
|
|
Asset retirement obligation |
0.0
|
|
0.0
|
|
|
Operating lease liabilities |
0.0
|
|
|
|
|
Deficit In excess of investment in subsidiaries |
(2,236.2)
|
|
(2,154.7)
|
|
|
Other liabilities |
0.0
|
|
0.0
|
|
|
Intercompany |
(165.1)
|
|
(181.7)
|
|
|
Total liabilities |
(2,593.0)
|
|
(2,503.2)
|
|
|
Total stockholders’ equity |
(2,519.2)
|
|
(2,467.5)
|
|
|
Non-controlling interests |
0.0
|
|
0.0
|
|
|
Total equity |
(2,519.2)
|
|
(2,467.5)
|
|
|
Total liabilities and equity |
$ (5,112.2)
|
|
$ (4,970.7)
|
|
|