Summary of Net Deferred Income Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components Of Deferred Tax Assets And Liabilities [Abstract]
Insurance	$ 48,430	$ 40,707
Accounts receivable allowances	34,029	9,562
Compensation	75,277	68,095
Net operating losses	179,074	120,263
Assets held for sale		2,458
Litigation	47,078
Other	57,683	42,130
Deferred Tax Assets, Gross, Total	441,571	283,215
Reclassification of deferred tax liabilities	(290,765)	(138,681)
Net deferred tax assets	150,806	144,534
Valuation allowance	(46,676)	(50,969)	$ (49,500)
Deferred Tax Assets, Net, Total	104,130	93,565
Property and equipment	24,968	10,276
Assets held for sale	189
Goodwill and intangibles	265,608	128,405
Reclassification of deferred tax liabilities	$ 290,765	$ 138,681