General - Health Care Reform (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2016	Dec. 31, 2015
General
Health Insurer Fee (HIF) fiscal year annual fees paid during the period						$ 26.5
Health Insurer Fee (HIF) projected fiscal year annual fees under Affordable Care Act					$ 26.3
HIF fees expensed	$ 6.1	$ 6.3	$ 13.2	$ 13.2
Amount of revenues associated with accrual for reimbursement of economic impact of HIF fees from its customers	$ 10.1	$ 10.7	$ 21.4	$ 22.4