Intangible Assets and Goodwill (Goodwill) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Line Items]
Goodwill before accumulated impairment				$ 1,265,120	$ 1,333,272
Accumulated impairment				(198,169)	(198,169)
Goodwill
Beginning balance			$ 1,066,951	1,135,103
Impairment	$ (220,000)	$ (119,000)	(339,184)	0	0
Acquisitions/(dispositions)				(53,107)
FX Impact			6,642	(15,045)
Ending balance	734,409		734,409	1,066,951	1,135,103
Global Ecommerce
Goodwill [Line Items]
Goodwill before accumulated impairment				537,353	593,231
Accumulated impairment				(198,169)	(198,169)
Goodwill
Beginning balance			339,184	395,062
Acquisitions/(dispositions)				(55,878)
FX Impact			0	0
Ending balance	0		0	339,184	395,062
Global Ecommerce | Operating Segments
Goodwill
Impairment	(220,000)	$ (119,000)	(339,184)
Presort Services
Goodwill [Line Items]
Goodwill before accumulated impairment				223,763	220,992
Accumulated impairment				0	0
Goodwill
Beginning balance			223,763	220,992
Acquisitions/(dispositions)				2,771
FX Impact			0	0
Ending balance	223,763		223,763	223,763	220,992
Presort Services | Operating Segments
Goodwill
Impairment			0
SendTech Solutions
Goodwill [Line Items]
Goodwill before accumulated impairment				504,004	519,049
Accumulated impairment				0	0
Goodwill
Beginning balance			504,004	519,049
Acquisitions/(dispositions)				0
FX Impact			6,642	(15,045)
Ending balance	$ 510,646		510,646	$ 504,004	$ 519,049
SendTech Solutions | Operating Segments
Goodwill
Impairment			$ 0