Significant Accounting Policies (Goodwill and Other Intangible Assets) (Details) (USD $)	12 Months Ended				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2013	Dec. 31, 2013 Provider Networks [Member]	Dec. 31, 2012 Provider Networks [Member]	Dec. 31, 2013 Customer Relationships [Member]	Dec. 31, 2012 Customer Relationships [Member]	Dec. 31, 2012 Western Region Operations [Member]	Dec. 31, 2013 Western Region Operations [Member]	Jun. 30, 2013 Western Region Operations [Member]	Jun. 30, 2012 Western Region Operations [Member]	Dec. 31, 2011 Western Region Operations [Member]
Significant Accounting Policies [Line Items]
Goodwill impairment				$ 0
Fair value to carrying value ratio											149.00%	115.00%
Goodwill	565,886,000	565,886,000	605,900,000						565,900,000	565,900,000			605,900,000
Goodwill allocated to business sold		(40,000,000)							(40,000,000)
Finite-Lived Intangible Assets
Gross Carrying Amount	70,000,000	70,000,000			40,500,000	40,500,000	29,500,000	29,500,000
Accumulated Amortization	(56,200,000)	(52,700,000)			(35,700,000)	(34,600,000)	(20,500,000)	(18,100,000)
Net Balance	13,800,000	17,300,000			4,800,000	5,900,000	9,000,000	11,400,000
Weighted Average Life (in years)					19 years 4 months 24 days	19 years 4 months 24 days	11 years 1 month 6 days	11 years 1 month 6 days
Amortization expense	3,400,000	3,400,000	3,500,000
Future Amortization Expense
Estimated annual pretax amortization expense, 2014	2,800,000
Estimated annual pretax amortization expense, 2015	2,600,000
Estimated annual pretax amortization expense, 2016	2,000,000
Estimated annual pretax amortization expense, 2017	2,000,000
Estimated annual pretax amortization expense, 2018	$ 2,000,000