Segment and Related Information - Reconciliation of the Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
SEGMENT AND RELATED INFORMATION
(Loss) income from operations	$ 17,403			$ 15,924			$ 38,527	$ 36,876
Interest expense, net	8,954			8,939			25,973	28,519
Loss on extinguishment of debt								16,998
Non-service defined benefit plan expense	173			176			519	528
Income (loss) before income taxes	8,276			6,809			12,035	(9,169)
Provision (benefit) for income taxes	2,585			2,440			3,260	(3,848)
Net income (loss)	5,691	$ 10,035	$ (6,951)	4,369	$ 12,928	$ (22,618)	8,775	(5,321)
Consolidated net revenues	279,638			262,946			797,155	763,907
Consolidated material costs	92,034			84,805			261,810	247,677
Corporate & other
SEGMENT AND RELATED INFORMATION
(Loss) income from operations	(23,838)			(23,417)			(69,267)	(67,910)
Consolidating adjustments
SEGMENT AND RELATED INFORMATION
Consolidated net revenues	(53,670)			(48,945)			(150,245)	(141,302)
Consolidated material costs	(53,670)			(48,945)			(150,245)	(141,302)
Patient Care
SEGMENT AND RELATED INFORMATION
(Loss) income from operations	36,130			32,502			93,661	84,615
Consolidated net revenues	230,931			214,080			652,700	620,745
Consolidated material costs	71,339			64,695			199,626	188,503
Patient Care | Operating segments
SEGMENT AND RELATED INFORMATION
Consolidated net revenues	230,931			214,080			652,700	620,745
Consolidated material costs	65,055			58,395			181,358	170,559
Products & Services
SEGMENT AND RELATED INFORMATION
(Loss) income from operations	5,111			6,839			14,133	20,171
Consolidated net revenues	102,377			97,811			294,700	284,464
Consolidated material costs	74,365			69,055			212,429	200,476
Products & Services | Operating segments
SEGMENT AND RELATED INFORMATION
Consolidated net revenues	48,707			48,866			144,455	143,162
Consolidated material costs	$ 26,979			$ 26,410			$ 80,452	$ 77,118