Annual report pursuant to Section 13 and 15(d)

SEGMENT INFORMATION (Financial Information by Geographic Area) (Detail)

v3.3.1.900
SEGMENT INFORMATION (Financial Information by Geographic Area) (Detail) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenue $ 666.3 $ 667.4 $ 678.1 $ 651.8 $ 624.6 $ 613.4 $ 613.9 $ 584.5 $ 2,663.6 $ 2,436.4 $ 2,303.9
Percentage of operating revenues                 100.00% 100.00% 100.00%
Long-lived assets 3,947.4       4,070.5       $ 3,947.4 $ 4,070.5  
Percentage of consolidated long-lived assets                 100.00% 100.00%  
U.S.                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenue                 $ 2,041.7 $ 1,810.2 $ 1,766.0
Percentage of operating revenues                 77.00% 74.00% 77.00%
Long-lived assets 3,248.3       3,287.5       $ 3,248.3 $ 3,287.5  
Percentage of consolidated long-lived assets                 82.00% 81.00%  
U.K.                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-lived assets 45.5       55.8       $ 45.5 $ 55.8  
Percentage of consolidated long-lived assets                 1.00% 1.00%  
Canada                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenue                 $ 224.1 $ 217.0 $ 144.7
Percentage of operating revenues                 8.00% 9.00% 6.00%
Long-lived assets 353.1       371.9       $ 353.1 $ 371.9  
Percentage of consolidated long-lived assets                 9.00% 9.00%  
Other                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenue                 $ 262.3 $ 255.0 $ 237.6
Percentage of operating revenues                 10.00% 11.00% 10.00%
Long-lived assets $ 300.5       $ 355.3       $ 300.5 $ 355.3  
Percentage of consolidated long-lived assets                 8.00% 9.00%