Summary of Significant Accounting Policies (Goodwill and Other Intangible Assets) (Details) (USD $)	3 Months Ended		12 Months Ended			9 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Jun. 30, 2014	Jun. 30, 2013
Significant Accounting Policies [Line Items]
Goodwill impairment							$ 0
Goodwill allocated to sale of business			7,000,000
Asset impairment	3,800,000	84,700,000	88,536,000	0	0
Goodwill	558,886,000		558,886,000	565,886,000	565,900,000
Finite-Lived Intangible Assets
Gross Carrying Amount	71,000,000		71,000,000	70,000,000
Accumulated Amortization	(59,200,000)		(59,200,000)	(56,200,000)
Net Balance	11,800,000		11,800,000	13,800,000
Amortization expense			3,000,000	3,400,000	3,400,000
Future Amortization Expense
Estimated annual pretax amortization expense, 2015	2,800,000		2,800,000
Estimated annual pretax amortization expense, 2016	2,200,000		2,200,000
Estimated annual pretax amortization expense, 2017	2,200,000		2,200,000
Estimated annual pretax amortization expense, 2018	2,100,000		2,100,000
Estimated annual pretax amortization expense, 2019	900,000		900,000
Provider Networks [Member]
Finite-Lived Intangible Assets
Gross Carrying Amount	41,500,000		41,500,000	40,500,000
Accumulated Amortization	(36,900,000)		(36,900,000)	(35,700,000)
Net Balance	4,600,000		4,600,000	4,800,000
Weighted Average Life (in years)			18 years 10 months 24 days	19 years 4 months 24 days
Customer Relationships [Member]
Finite-Lived Intangible Assets
Gross Carrying Amount	29,500,000		29,500,000	29,500,000
Accumulated Amortization	(22,300,000)		(22,300,000)	(20,500,000)
Net Balance	7,200,000		7,200,000	9,000,000
Weighted Average Life (in years)			11 years 1 month 6 days	11 years 1 month 6 days
Western Region Operations [Member]
Significant Accounting Policies [Line Items]
Goodwill allocated to sale of business			7,000,000
Fair value to carrying value ratio		224.00%				224.00%		149.00%
Goodwill	558,900,000		558,900,000	565,900,000	565,900,000
Goodwill [Member]
Significant Accounting Policies [Line Items]
Asset impairment			$ 7,000,000			$ 7,000,000