Segment Information (Capital Expenditures) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Capital expenditures	$ 137,253	$ 137,810	$ 118,247
Commerce Services | Global Ecommerce
Segment Reporting Information [Line Items]
Capital expenditures	53,374	46,073	26,810
Commerce Services | Presort Services
Segment Reporting Information [Line Items]
Capital expenditures	27,394	42,531	20,860
Corporate
Segment Reporting Information [Line Items]
Capital expenditures	24,209	24,558	30,132
Operating Segments
Segment Reporting Information [Line Items]
Capital expenditures	113,044	113,252	88,115
Operating Segments | Commerce Services
Segment Reporting Information [Line Items]
Capital expenditures	80,768	88,604	47,670
Operating Segments | SendTech Solutions
Segment Reporting Information [Line Items]
Capital expenditures	$ 32,276	$ 24,648	$ 40,445