Reinsurance

We reinsure certain risks with other companies and assume risk from other companies. We remain primarily liable to policyholders under ceded insurance contracts and are contingently liable for amounts recoverable from reinsurers in the event that such reinsurers do not meet their contractual obligations. We evaluate the financial condition of our reinsurers and monitor concentrations of credit risk arising from similar geographic regions, activities, or economic characteristics of the reinsurers to minimize our exposure to significant losses from reinsurer insolvencies. In conjunction with the Health Care Reform temporary reinsurance premium stabilization program, we recognize assessments upon our fully-insured non-grandfathered individual market plans that are eligible for reinsurance recoveries as ceded premiums and estimated reinsurance recoveries as a reduction to benefit expense. Assessments upon all other lines of business not eligible for reinsurance recoveries are recognized in general and administrative expense.

A summary of direct, assumed and ceded premiums written and earned for the years ended December 31 is as follows:



	2015						2014						2013
	Written			Earned			Written			Earned			Written			Earned
Direct	$	72,925.5		$	73,259.2		$	68,628.6		$	68,304.3		$	65,939.1		$	66,038.9
Assumed	221.8			221.9			192.3			194.0			174.3			174.0
Ceded	(95.8		)	(96.0		)	(108.5		)	(108.5		)	(92.6		)	(93.8		)
Net premiums	$	73,051.5		$	73,385.1		$	68,712.4		$	68,389.8		$	66,020.8		$	66,119.1
Percentage—assumed to net premiums	0.3		%	0.3		%	0.3		%	0.3		%	0.3		%	0.3		%

A summary of net premiums written and earned by segment (see Note 19, “Segment Information”) for the years ended December 31 is as follows:



	2015				2014				2013
	Written		Earned		Written		Earned		Written		Earned
Reportable segments:
Commercial and Specialty Business	$	33,016.9	$	33,078.0	$	35,084.7	$	35,045.2	$	35,733.9	$	35,772.0
Government Business	40,034.6		40,307.1		33,627.7		33,344.6		30,286.9		30,347.1
Other	—		—		—		—		—		—
Net premiums	$	73,051.5	$	73,385.1	$	68,712.4	$	68,389.8	$	66,020.8	$	66,119.1

The effect of reinsurance on benefit expense for the years ended December 31 is as follows:



	2015			2014			2013
Direct	$	61,674.0		$	57,496.6		$	56,185.2
Assumed	192.2			182.4			155.6
Ceded	(749.3		)	(824.1		)	(103.7		)
Net benefit expense	$	61,116.9		$	56,854.9		$	56,237.1

The effect of reinsurance on certain assets and liabilities at December 31 is as follows:



	2015		2014
Policy liabilities, assumed	$	56.7	$	57.4
Unearned income, assumed	0.5		0.4
Premiums payable, ceded	9.3		7.7
Premiums receivable, assumed	23.2		5.4