Subsequent Event (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended										0 Months Ended
	Sep. 30, 2013	Sep. 30, 2013 Revolving Credit Facility [Member]	Sep. 30, 2013 Harden Healthcare Holdings Inc. [Member]	Oct. 18, 2013 Subsequent Event [Member] Federal Funds [Member]	Oct. 18, 2013 Subsequent Event [Member] London Interbank Offered Rate (LIBOR) [Member]	Oct. 18, 2013 Subsequent Event [Member] Term Loan B [Member]	Oct. 18, 2013 Subsequent Event [Member] Term Loan C [Member]	Oct. 18, 2013 Subsequent Event [Member] Revolving Credit Facility [Member]	Oct. 18, 2013 Subsequent Event [Member] Letter of Credit [Member]	Oct. 18, 2013 Subsequent Event [Member] Same-Day Borrowing [Member]	Oct. 18, 2013 Subsequent Event [Member] Harden Healthcare Holdings Inc. [Member]
Subsequent Event [Line Items]
Business Combination, Consideration Transferred	$ 6.1										$ 408.8
Payments to Acquire Businesses, Gross											355.0
Stock Issued During Period, Value, Acquisitions											53.8
Business Acquisition, Transaction Costs			1.5
Debt instrument, face amount						670	155
Line of Credit Facility, Maximum Borrowing Capacity		$ 110						$ 100	$ 80	$ 15
Effective interest rate				0.50%	1.00%
Annual principal payment percentage rate						1.00%