Acquisitions (Details 3) (Brink's Home Security Holdings, Inc., now operating as Broadview Security, USD $) In Millions, unless otherwise specified	1 Months Ended
	May 31, 2010 Y	May 14, 2010
Brink's Home Security Holdings, Inc., now operating as Broadview Security
Business Acquisition Purchase Price Allocation
Net current assets		$ 78
Subscriber systems		624
Other property, plant and equipment		49
Total property, plant and equipment		673
Contracts and related customer relationships		738
Other intangible assets		12
Total intangible assets		750
Net non-current liabilities		(459)
Net assets acquired		1,042
Goodwill		932
Purchase price		1,974
Contracts and related customer relationships, weighted-average useful life (in years)	10
Other intangible assets, weighted-average useful life (in years)	4
Fair value of acquired receivables, net		32
Fair value of acquired receivables, gross		35
Acquired receivables, allowance for uncollectible amounts		3
Acquired deferred tax liabilities		$ 456