Segment Information (Depreciation and Amortization) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 203,293	$ 179,650	$ 174,065
Digital Commerce Solutions | Global Ecommerce
Segment Reporting Information [Line Items]
Depreciation and amortization	61,046	36,662	30,607
Digital Commerce Solutions | Presort Services
Segment Reporting Information [Line Items]
Depreciation and amortization	26,838	26,541	27,929
SMB Solutions | North America Mailing
Segment Reporting Information [Line Items]
Depreciation and amortization	68,250	64,803	60,066
SMB Solutions | International Mailing
Segment Reporting Information [Line Items]
Depreciation and amortization	16,142	18,562	19,431
Operating Segments
Segment Reporting Information [Line Items]
Depreciation and amortization	181,816	155,546	152,654
Operating Segments | Digital Commerce Solutions
Segment Reporting Information [Line Items]
Depreciation and amortization	87,884	63,203	58,536
Operating Segments | SMB Solutions
Segment Reporting Information [Line Items]
Depreciation and amortization	84,392	83,365	79,497
Operating Segments | Software Solutions
Segment Reporting Information [Line Items]
Depreciation and amortization	9,540	8,978	14,621
Unallocated amount
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 21,477	$ 24,104	$ 21,411