Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts and Bilinig Adjustments
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 4,404	$ 2,465	$ 3,395
Provisions	10,486	6,680	1,474
Deductions	(8,208)	(4,741)	(2,404)
Balance at end of year	6,682	4,404	2,465
Allowance for Workers' Compensation and Medical Malpractice Loss Reserves
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	15,564	17,123	17,037
Provisions	2,117	2,211	5,850
Deductions	(2,661)	(3,770)	(5,764)
Balance at end of year	$ 15,020	$ 15,564	$ 17,123