Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions We have a 19.50% equity investment in National Accounts Service Company, LLC, or NASCO, which processes National Accounts claims and provides other administrative services for us and certain other Blue Cross Blue Shield plans. Administrative expenses incurred related to NASCO services totaled $79.7, $83.6 and $85.3, for the years ended December 31, 2016, 2015 and 2014, respectively. Amounts due to NASCO were $6.2 and $5.4 at December 31, 2016 and 2015, respectively.

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.