Segment Information (Tables)

12 Months Ended

Dec. 31, 2017

Segment Reporting [Abstract]

Financial Data By Reportable Segment

Financial data by reportable segment for the years ended December 31, 2017, 2016 and 2015 is as follows:

	Commercial & Specialty Business		Government Business		Other			Total
Year ended December 31, 2017
Operating revenue	$	40,754.1	$	48,276.2	$	30.9		$	89,061.2
Operating gain (loss)	2,876.1		1,430.2		(130.9		)	4,175.4
Depreciation and amortization of property and equipment	—		—		601.0			601.0
Year ended December 31, 2016
Operating revenue	$	38,692.1	$	45,477.7	$	24.2		$	84,194.0
Operating gain (loss)	3,195.2		1,784.3		(177.8		)	4,801.7
Depreciation and amortization of property and equipment	—		—		576.0			576.0
Year ended December 31, 2015
Operating revenue	$	37,570.8	$	40,813.0	$	21.0		$	78,404.8
Operating gain (loss)	2,854.0		1,978.5		(79.4		)	4,753.1
Depreciation and amortization of property and equipment	—		—		515.6			515.6

Major Product Revenues

The major product revenues for each of the reportable segments for the years ended December 31, 2017, 2016 and 2015 are as follows:

	2017		2016		2015
Commercial & Specialty Business
Managed care products	$	34,272.1	$	32,369.8	$	31,676.9
Managed care services	4,821.0		4,710.1		4,344.8
Dental/Vision products and services	1,218.1		1,182.3		1,111.7
Other	442.9		429.9		437.4
Total Commercial & Specialty Business	40,754.1		38,692.1		37,570.8
Government Business
Managed care products	47,843.4		45,028.5		40,307.0
Managed care services	432.8		449.2		506.0
Total Government Business	48,276.2		45,477.7		40,813.0
Other
Other	30.9		24.2		21.0
Total product revenues	$	89,061.2	$	84,194.0	$	78,404.8

Reconciliation Of Reportable Segment Operating Revenues To The Consolidated Statements Of Income

A reconciliation of reportable segment operating revenues to the amounts of total revenues included in the consolidated statements of income for the years ended December 31, 2017, 2016 and 2015 is as follows:

	2017			2016			2015
Reportable segments operating revenues	$	89,061.2		$	84,194.0		$	78,404.8
Net investment income	866.5			779.5			677.6
Net realized gains on financial instruments	144.8			4.9			157.5
Other-than-temporary impairment losses recognized in income	(33.1		)	(115.4		)	(83.4		)
Total revenues	$	90,039.4		$	84,863.0		$	79,156.5

Reconciliation Of Reportable Segment Operating Gain To Income From Continuing Operations Before Income Taxes In The Consolidated Statements Of Income

A reconciliation of reportable segment operating gain to income before income tax expense included in the consolidated statements of income for the years ended December 31, 2017, 2016 and 2015 is as follows:

	2017			2016			2015
Reportable segments operating gain	$	4,175.4		$	4,801.7		$	4,753.1
Net investment income	866.5			779.5			677.6
Net realized gains on financial instruments	144.8			4.9			157.5
Other-than-temporary impairment losses recognized in income	(33.1		)	(115.4		)	(83.4		)
Interest expense	(739.0		)	(723.0		)	(653.0		)
Amortization of other intangible assets	(168.4		)	(192.3		)	(230.1		)
(Loss) gain on extinguishment of debt	(282.4		)	—			9.3
Income before income tax expense	$	3,963.8		$	4,555.4		$	4,631.0