Goodwill and other intangible assets (Tables)

6 Months Ended

Jun. 30, 2011

Goodwill and other intangible assets [Abstract]

Summary of goodwill and other intangible assets

	June 30, 2011							December 31, 2010
	Gross					Net		Gross					Net
	Carrying		Accumulated			Carrying		Carrying		Accumulated			Carrying
(in millions)	Amount		Amortization			Amount		Amount		Amortization			Amount
Goodwill
PBM	$	5,462.1	$	(107.6	)	$	5,354.5	$	5,461.3	$	(107.4	)	$	5,353.9
EM		132.3		—			132.3		132.3		—			132.3
	$	5,594.4	$	(107.6	)	$	5,486.8	$	5,593.6	$	(107.4	)	$	5,486.2
Other intangible assets
PBM
Customer contracts	$	2,018.9	$	(420.7	)	$	1,598.2	$	2,018.7	$	(346.4	)	$	1,672.3
Other		31.7		(7.4	)		24.3		20.8		(5.0	)		15.8
		2,050.6		(428.1	)		1,622.5		2,039.5		(351.4	)		1,688.1
EM
Customer relationships		68.4		(35.4	)		33.0		68.4		(32.2	)		36.2
Other		0.7		—			0.7		0.7		—			0.7
		69.1		(35.4	)		33.7		69.1		(32.2	)		36.9
Total other intangible assets	$	2,119.7	$	(463.5	)	$	1,656.2	$	2,108.6	$	(383.6	)	$	1,725.0

Summary of change in net carrying value of goodwill by business segment

(in millions)	PBM		EM		Total
Balance at December 31, 2010	$	5,353.9	$	132.3	$	5,486.2
Foreign currency translation		0.6		—		0.6
Balance at June 30, 2011	$	5,354.5	$	132.3	$	5,486.8