Annual report pursuant to Section 13 and 15(d)

SEGMENT INFORMATION - Financial Information by Geographic Area (Details)

v3.20.4
SEGMENT INFORMATION - Financial Information by Geographic Area (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Dec. 31, 2020
Sep. 30, 2020
Jun. 30, 2020
Mar. 31, 2020
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenue $ 1,118.5 $ 1,068.3 $ 982.8 $ 957.9 $ 905.8 $ 875.7 $ 880.0 $ 846.1 $ 4,127.5 $ 3,507.6 $ 3,412.1
Percentage of operating revenues                 100.00% 100.00% 100.00%
Long-lived assets 7,133.5       6,699.6       $ 7,133.5 $ 6,699.6  
Percentage of consolidated long-lived assets                 100.00% 100.00%  
U.S.                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenue                 $ 3,217.1 $ 2,543.2 $ 2,405.1
Percentage of operating revenues                 78.00% 73.00% 71.00%
Long-lived assets 4,005.7       3,911.5       $ 4,005.7 $ 3,911.5  
Percentage of consolidated long-lived assets                 56.00% 58.00%  
U.K.                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenue                 $ 285.2 $ 303.8 $ 316.4
Percentage of operating revenues                 7.00% 9.00% 9.00%
Long-lived assets 319.3       312.8       $ 319.3 $ 312.8  
Percentage of consolidated long-lived assets                 5.00% 5.00%  
Australia                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenue                 $ 282.6 $ 289.9 $ 321.2
Percentage of operating revenues                 7.00% 5.00% 9.00%
Long-lived assets 2,021.2       1,918.6       $ 2,021.2 $ 1,918.6  
Percentage of consolidated long-lived assets                 28.00% 29.00%  
Canada                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenue                 $ 168.4 $ 170.0 $ 158.5
Percentage of operating revenues                 4.00% 8.00% 5.00%
Long-lived assets 133.9       128.0       $ 133.9 $ 128.0  
Percentage of consolidated long-lived assets                 2.00% 2.00%  
Other                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenue                 $ 174.2 $ 200.7 $ 210.9
Percentage of operating revenues                 4.00% 5.00% 6.00%
Long-lived assets $ 653.4       $ 428.7       $ 653.4 $ 428.7  
Percentage of consolidated long-lived assets                 9.00% 6.00%