Accrued Professional Liabilities - Rollforward of Reserves (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Self Insurance Reserve [Roll Forward]
Balance at December 31, 2014	$ 53,785
Assumed liabilities through acquisitions	4,301
Provision related to current period reserves	3,300
Payments for current period reserves	(1,551)
Payments for prior period reserves	(2,294)
Balance at March 31, 2015	$ 57,541