Segment Information (Net Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Reconciliation of adjusted segment EBIT to net income or loss from continuing operations before income taxes:
Interest expense, net	$ (27,764)	$ (26,363)	$ (83,323)	$ (70,822)
Restructuring charges	(30,694)	(13,942)	(64,859)	(34,768)
Goodwill impairment	0	0	0	(43,209)
(Loss) gain on debt refinancing	(2,142)		(2,142)	3,064
Asset impairment			(10,000)	(43,209)
(Loss) income from continuing operations before taxes	(43,880)	26,927	(4,130)	18,632
Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBIT	150,407	128,344	420,029	368,163
Operating Segments | SendTech Solutions
Segment Reporting Information [Line Items]
Adjusted EBIT	104,228	99,220	306,473	291,705
Operating Segments | Presort Services
Segment Reporting Information [Line Items]
Adjusted EBIT	46,179	29,124	113,556	76,458
Other
Segment Reporting Information [Line Items]
Adjusted EBIT	(4,236)	(2,595)	(4,824)	(1,017)
Segment Reconciling Items
Reconciliation of adjusted segment EBIT to net income or loss from continuing operations before income taxes:
Interest expense, net	(43,859)	(43,176)	(131,986)	(116,934)
Corporate expenses	(43,386)	(41,704)	(144,431)	(145,762)
Restructuring charges	(30,694)	(13,942)	(64,859)	(34,768)
Goodwill impairment	0	0	0	(43,209)
Proxy solicitation fees	0	0	0	(10,905)
(Loss) gain on debt refinancing	(2,142)	0	(2,142)	3,064
Foreign currency loss on intercompany loans	(18,831)	0	(13,481)	0
Asset impairment	(10,000)	0	(10,000)	0
Strategic review costs	(2,994)	0	(14,291)	0
Segment Reconciling Items | Ecommerce | Discontinued Operations, Disposed of by Sale
Reconciliation of adjusted segment EBIT to net income or loss from continuing operations before income taxes:
Restructuring charges	$ (38,145)	$ 0	$ (38,145)	$ 0