Segment Reporting Total Assets (Details) (USD $) In Millions	Sep. 24, 2011	Dec. 25, 2010
Segment Reporting Information [Line Items]
Total assets	$ 12,429.9	$ 12,697.6
Canada
Segment Reporting Information [Line Items]
Total assets	6,467.0	6,548.9
U.S.
Segment Reporting Information [Line Items]
Total assets	2,589.6	2,574.1
U.K.
Segment Reporting Information [Line Items]
Total assets	2,172.4	2,276.2
MCI and Corporate
Segment Reporting Information [Line Items]
Total assets	1,200.6	1,297.8
Discontinued operations
Segment Reporting Information [Line Items]
Total assets	$ 0.3	$ 0.6