Goodwill and Intangibles - Summary of Changes in Intangible Assets (Details) $ in Thousands	9 Months Ended
Sep. 30, 2018 USD ($)
Finite-lived Intangible Assets [Roll Forward]
Balance as of December 31, 2017	$ 134,610
Definite lived assets, Acquisitions	170,396
Amortization	(1,748)
Adjustments & disposals	(1,847)
Balance as of September 30, 2018	301,411
Trade Names
Finite-lived Intangible Assets [Roll Forward]
Balance as of December 31, 2017	2,580
Indefinite lived assets, Acquisitions	0
Amortization	(1,103)
Adjustments & disposals	0
Balance as of September 30, 2018	1,477
Customer relationships
Finite-lived Intangible Assets [Roll Forward]
Balance as of December 31, 2017	0
Definite lived assets, Acquisitions	13,970
Amortization	(457)
Adjustments & disposals	0
Balance as of September 30, 2018	13,513
Non-compete agreements
Finite-lived Intangible Assets [Roll Forward]
Balance as of December 31, 2017	238
Definite lived assets, Acquisitions	178
Amortization	(188)
Adjustments & disposals	0
Balance as of September 30, 2018	228
Trade Names
Finite-lived Intangible Assets [Roll Forward]
Balance as of December 31, 2017	78,299
Indefinite lived assets, Acquisitions	77,463
Amortization	0
Adjustments & disposals	0
Balance as of September 30, 2018	155,762
Certificates of need/licenses
Finite-lived Intangible Assets [Roll Forward]
Balance as of December 31, 2017	53,493
Indefinite lived assets, Acquisitions	78,785
Amortization	0
Adjustments & disposals	(1,847)
Balance as of September 30, 2018	$ 130,431

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition.

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Amount of increase (decrease) of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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