Goodwill and Other Intangible Assets (Tables)
 12 Months Ended
Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule of Change in Goodwill and Other Intangible Assets
The changes in the carrying amount of goodwill by operating segment for the years ended December 31, 2017 and 2016 are as follows:
 
December 31, 2017
(In millions)
Beginning Balance
 
Acquisitions/
Dispositions
 
Currency
 
Ending Balance
 
 
 
 
 
 
 
 
Goodwill:
 
 
 
 
 
 
 
North America
$
23.9

 
7.8

 
0.3

 
32.0

South America
27.1

 
203.7

 
(15.9
)
 
214.9

Rest of World
135.2

 
55.0

 
16.6

 
206.8

Total Goodwill
$
186.2

 
266.5

 
1.0

 
453.7


 
December 31, 2016
(In millions)
Beginning Balance
 
Acquisitions/
Dispositions
 
Currency
 
Ending Balance
 
 
 
 
 
 
 
 
Goodwill:
 
 
 
 
 
 
 
North America
$
22.3

 
—

 
1.6

 
23.9

South America
23.0

 
—

 
4.1

 
27.1

Rest of World
140.0

 
(0.2
)
 
(4.6
)
 
135.2

Total Goodwill
$
185.3

 
(0.2
)
 
1.1

 
186.2
Schedule of Intangible Assets and Goodwill
The following table summarizes our other intangible assets by category:
 
December 31, 2017
 
December 31, 2016
 
 
(In millions)
Gross Carrying Amount
 
Accumulated Amortization
 
Net Carrying Amount
 
Gross Carrying Amount
 
Accumulated Amortization
 
Net Carrying Amount
 
Weighted-average amortization period
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Customer relationships
137.5

 
(51.9
)
 
85.6

 
50.2

 
(43.5
)
 
6.7

 
8.9

Indefinite-lived trade names
7.9

 
—

 
7.9

 
7.5

 
—

 
7.5

 
—

Finite-lived trade names
8.4

 
(2.3
)
 
6.1

 
1.3

 
(1.2
)
 
0.1

 
3.8

Other contract-related assets
6.6

 
(3.0
)
 
3.6

 
6.7

 
(2.4
)
 
4.3

 
6.6

Other
6.5

 
(4.0
)
 
2.5

 
3.7

 
(3.2
)
 
0.5

 
2.1

Total
$
166.9

 
(61.2
)
 
105.7

 
$
69.4

 
(50.3
)
 
19.1

 
 
Schedule of Expected Amortization Expense
Our estimated aggregate amortization expense for finite-lived intangibles recorded at December 31, 2017, for the next five years is as follows:

(In millions)
2018
 
2019
 
2020
 
2021
 
2022
 
 
 
 
 
 
 
 
 
 
Amortization expense
$
14.7

 
13.3

 
11.5

 
11.1

 
9.7