Segment and Related Information - Reconciliation of the Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Segment and Related Information
Income from operations	$ 13,075			$ 17,403			$ 42,763	$ 38,527
Interest expense, net	8,013			8,954			24,918	25,973
Non-service defined benefit plan expense	158			173			474	519
Income before income taxes	4,904			8,276			17,371	12,035
(Benefit) provision for income taxes	(1,911)			2,585			(4,750)	3,260
Net income	6,815	$ 31,054	$ (15,748)	5,691	$ 10,035	$ (6,951)	22,121	8,775
Consolidated net revenues	256,637			279,638			723,810	797,155
Consolidated material costs	81,462			92,034			228,675	261,810
Consolidated purchase of property, plant and equipment							19,352	20,262
Consolidated assets	952,681						952,681		$ 842,253
Corporate & other
Segment and Related Information
Income from operations	(24,284)			(23,838)			(72,590)	(69,267)
Consolidating adjustments
Segment and Related Information
Consolidated net revenues	(50,011)			(53,670)			(138,899)	(150,245)
Consolidated material costs	(50,011)			(53,670)			(138,899)	(150,245)
Patient Care
Segment and Related Information
Income from operations	32,238			36,130			102,394	93,661
Consolidated net revenues	212,664			230,931			598,706	652,700
Consolidated material costs	63,938			71,339			178,851	199,626
Patient Care | Operating segments
Segment and Related Information
Consolidated net revenues	212,664			230,931			598,706	652,700
Consolidated material costs	56,599			65,055			160,212	181,358
Products & Services
Segment and Related Information
Income from operations	5,121			5,111			12,959	14,133
Consolidated net revenues	93,984			102,377			264,003	294,700
Consolidated material costs	67,535			74,365			188,723	212,429
Products & Services | Operating segments
Segment and Related Information
Consolidated net revenues	43,973			48,707			125,104	144,455
Consolidated material costs	$ 24,863			$ 26,979			$ 68,463	$ 80,452