Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue Recognition
Net revenues	$ 300,891	$ 279,638	$ 281,098	$ 236,419	$ 284,853	$ 262,946	$ 266,966	$ 233,995	$ 1,098,046	$ 1,048,760	$ 1,040,769
Patient Care
Revenue Recognition
Net revenues									905,691	857,382	851,973
Patient Care | Medicare
Revenue Recognition
Net revenues									289,099	273,833	260,275
Patient Care | Medicaid
Revenue Recognition
Net revenues									143,438	132,938	132,707
Patient Care | Commercial Insurance/ Managed Care (excluding Medicare and Medicaid Managed Care)
Revenue Recognition
Net revenues									323,499	316,243	325,639
Patient Care | Veterans Administration
Revenue Recognition
Net revenues									89,035	78,328	74,435
Patient Care | Private Pay
Revenue Recognition
Net revenues									60,620	56,040	58,917
Patient Care | Operating segments
Revenue Recognition
Net revenues									905,691	857,382	851,973
Products & Services
Revenue Recognition
Net revenues									192,355	191,378	188,796
Products & Services | Distribution services, net of intersegment revenue eliminations
Revenue Recognition
Net revenues									143,400	135,995	128,686
Products & Services | Therapeutic solutions
Revenue Recognition
Net revenues									48,955	55,383	60,110
Products & Services | Operating segments
Revenue Recognition
Net revenues									$ 395,851	$ 383,474	$ 367,564