Medical Costs Payable (Tables)

6 Months Ended

Jun. 30, 2018

Insurance [Abstract]

Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block]

The following table shows the components of the change in medical costs payable for the six months ended June 30:

(in millions)	2018			2017
Medical costs payable, beginning of period	$	17,871		$	16,391
Acquisitions	261			76
Reported medical costs:
Current year	72,570			65,208
Prior years	(280		)	(580		)
Total reported medical costs	72,290			64,628
Medical payments:
Payments for current year	(55,738		)	(49,673		)
Payments for prior years	(15,345		)	(13,712		)
Total medical payments	(71,083		)	(63,385		)
Medical costs payable, end of period	$	19,339		$	17,710