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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Acquisition (Amortization Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Amortization of Intangible Assets	$ 13,000	$ 13,100	$ 5,000
2021		6,828
2022		5,439
2023		3,432
2024		3,172
2025		2,148
Thereafter		3,384
Finite-Lived Intangible Assets, Net		24,403
Quarton
Business Acquisition [Line Items]
Amortization of Intangible Assets	8,900	$ 8,900
MHT Partners [Member]
Business Acquisition [Line Items]
Amortization of Intangible Assets	100
Scenario, Plan \| Quarton
Business Acquisition [Line Items]
2021	2,608
2022	1,775
2023	0
2024	0
2025	0
Thereafter	0
Finite-Lived Intangible Assets, Net	4,383
Scenario, Plan \| MHT Partners [Member]
Business Acquisition [Line Items]
2021	300
2022	300
2023	289
2024	209
2025	52
Thereafter	0
Finite-Lived Intangible Assets, Net	$ 1,150