Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2013	Mar. 31, 2013 segment	Jun. 30, 2012	Jun. 30, 2013 segment	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting [Abstract]
Number of operating segments		2		3
Summary of financial information of segments
Assets	$ 3,347.4			$ 3,347.4		$ 3,392.5
Operating revenues	485.1		465.5	980.3	941.4	1,892.4	1,744.0
Out-of-pocket reimbursements	172.0		167.3	359.2	344.6	684.2	644.7
Total revenues	657.1		632.8	1,339.5	1,286.0	2,576.6	2,388.7
Costs and expenses	551.3		539.6	1,125.9	1,098.7	2,202.9	1,997.0
Depreciation and amortization	33.1		42.3	66.3	76.3	216.4	131.6
Income from operations	72.7		50.9	147.3	111.0	157.3	260.1
Other income (loss), net	28.4		194.2	101.6	223.9	373.5	38.7
Equity in earnings of unconsolidated affiliates	9.5		1.4	15.1	6.7	32.2	21.7
Earnings (loss) before interest and income taxes	110.6		246.5	264.0	341.6	563.0	320.5
Interest expense	9.3		11.7	18.9	23.4	(43.5)	(46.5)
Financial Services
Summary of financial information of segments
Assets	1,501.0			1,501.0		1,589.0
Operating revenues	238.4		229.6	476.4	463.8	935.0	858.8
Intersegment operating revenues	10.3		10.8	21.1	21.6	43.6	40.4
Out-of-pocket reimbursements	11.1		11.7	23.1	24.9	49.7	36.8
Total revenues	259.8		252.1	520.6	510.3	1,028.3	936.0
Costs and expenses	192.6		189.0	390.2	383.2	777.0	657.2
Depreciation and amortization	15.5		23.0	31.3	39.3	74.3	56.9
Income from operations	51.7		40.1	99.1	87.8	177.0	221.9
Other income (loss), net	1.9		0.6	(2.6)	5.4	8.1	8.0
Equity in earnings of unconsolidated affiliates	8.1		0.9	11.6	5.3	27.6	22.0
Earnings (loss) before interest and income taxes	61.7		41.6	108.1	98.5	212.7	251.9
Healthcare Services
Summary of financial information of segments
Assets	295.9			295.9		382.1
Operating revenues	82.0		75.8	162.0	150.7	300.6	270.8
Intersegment operating revenues
Out-of-pocket reimbursements	1.4		1.4	2.7	2.7	5.1	5.3
Total revenues	83.4		77.2	164.7	153.4	305.7	276.1
Costs and expenses	67.3		64.3	136.8	131.4	255.9	240.5
Depreciation and amortization	4.7		4.2	9.4	8.9	17.7	19.6
Income from operations	11.4		8.7	18.5	13.1	32.1	16.0
Other income (loss), net				0.1	0.2	0.3	(1.4)
Equity in earnings of unconsolidated affiliates	0.1			0.2	0.1	0.3
Earnings (loss) before interest and income taxes	11.5		8.7	18.8	13.4	32.7	14.6
Customer Communications
Summary of financial information of segments
Assets	380.5			380.5		385.5
Operating revenues	160.8		156.5	334.0	319.9	642.0	602.1
Intersegment operating revenues	2.0		2.2	4.0	4.2	8.0	7.7
Out-of-pocket reimbursements	161.2		156.1	337.1	320.8	636.7	607.0
Total revenues	324.0		314.8	675.1	644.9	1,286.7	1,216.8
Costs and expenses	304.7		299.1	625.8	611.0	1,214.9	1,148.9
Depreciation and amortization	11.0		11.1	21.8	22.1	107.4	46.7
Income from operations	8.3		4.6	27.5	11.8	(35.6)	21.2
Other income (loss), net	0.5			(0.3)		0.1	0.1
Equity in earnings of unconsolidated affiliates				0.1	0.2	0.5	0.6
Earnings (loss) before interest and income taxes	8.8		4.6	27.3	12.0	(35.0)	21.9
Investments and Other
Summary of financial information of segments
Assets	1,234.7			1,234.7		1,102.3
Operating revenues	3.9		3.6	7.9	7.0	14.8	12.3
Intersegment operating revenues	10.5		11.5	20.8	22.5	44.1	44.0
Out-of-pocket reimbursements					0.1	0.3	1.6
Total revenues	14.4		15.1	28.7	29.6	59.2	57.9
Costs and expenses	8.7		11.0	17.5	20.0	47.9	38.0
Depreciation and amortization	2.6		4.6	5.1	7.3	19.6	11.0
Income from operations	3.1		(0.5)	6.1	2.3	(8.3)	8.9
Other income (loss), net	26.0		193.6	104.4	218.3	365.0	32.0
Equity in earnings of unconsolidated affiliates	1.3		0.5	3.2	1.1	3.8	(0.9)
Earnings (loss) before interest and income taxes	30.4		193.6	113.7	221.7	360.5	40.0
Elimination Adjustments
Summary of financial information of segments
Assets	(64.7)			(64.7)		(66.4)
Intersegment operating revenues	(22.8)		(24.5)	(45.9)	(48.3)	(95.7)	(92.1)
Out-of-pocket reimbursements	(1.7)		(1.9)	(3.7)	(3.9)	(7.6)	(6.0)
Total revenues	(24.5)		(26.4)	(49.6)	(52.2)	(103.3)	(98.1)
Costs and expenses	(22.0)		(23.8)	(44.4)	(46.9)	(92.8)	(87.6)
Depreciation and amortization	(0.7)		(0.6)	(1.3)	(1.3)	(2.6)	(2.6)
Income from operations	(1.8)		(2.0)	(3.9)	(4.0)	(7.9)	(7.9)
Earnings (loss) before interest and income taxes	$ (1.8)		$ (2.0)	$ (3.9)	$ (4.0)	$ (7.9)	$ (7.9)