Segment And Geographic Information (Schedule Of Financial Information By Geographic Segment) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Segment and geographic information [Line Items]
Total revenues		$ 285,209	$ 265,898	$ 563,692	$ 499,295
Facility gross profit		89,729	82,524	172,174	149,794
Depreciation and amortization		22,242	22,162	44,811	42,884
Capital expenditures	[1]			27,600	45,391
Total assets		1,147,031		1,147,031		$ 1,146,724
Property and equipment		260,065		260,065		270,757
Acquisition-related goodwill and intangible assets				570,554		551,276
U. S Domestic [Member]
Segment and geographic information [Line Items]
Total revenues		254,122	241,598	503,285	453,823
Facility gross profit		71,635	69,089	137,240	124,937
Depreciation and amortization		20,754	20,924	41,834	40,412
Capital expenditures	[1]			24,905	36,504
Total assets		993,825		993,825		997,136
Property and equipment		229,166		229,166		239,203
Acquisition-related goodwill and intangible assets				505,131		483,214
International [Member]
Segment and geographic information [Line Items]
Total revenues		31,087	24,300	60,407	45,472
Facility gross profit		18,094	13,435	34,934	24,857
Depreciation and amortization		1,488	$ 1,238	2,977	2,472
Capital expenditures	[1]			2,695	$ 8,887
Total assets		153,206		153,206		149,588
Property and equipment		$ 30,899		30,899		31,554
Acquisition-related goodwill and intangible assets				$ 65,423		$ 68,062

[1] includes capital lease obligations related to capital expenditures