Business Combinations - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Feb. 17, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 616,180		$ 493,890
LCS Facilities
Business Acquisition [Line Items]
Accounts receivable		$ 9,395
Prepaid expenses and other current assets		183
Property and equipment		119,726
Intangible assets		73,200
Total assets acquired		202,504
Accounts payable and accrued expenses		2,442
Total identifiable net assets		200,062
Goodwill		107,341
Total consideration paid		$ 307,403