Acquisitions, Divestiture, Intangible Assets and Goodwill (Goodwill) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Line Items]
Gross value before accumulated impairment						$ 1,745,957	$ 1,672,721
Accumulated impairment						0	0
Goodwill	$ 1,571,335	$ 1,745,957	$ 1,672,721	$ 1,672,721		1,745,957	1,672,721
Goodwill [Roll Forward]
Balance at		1,745,957	1,672,721
Acquisition		21,329	307,562
Impairment	(171,000)	(171,092)	0	0
Other		(24,859)	(234,326)
Balance at	1,571,335	1,571,335	1,745,957	1,672,721
North America Mailing
Goodwill [Line Items]
Gross value before accumulated impairment						296,053	309,448
Accumulated impairment						0	0
Goodwill	292,838	296,053	309,448	309,448		296,053	309,448
Goodwill [Roll Forward]
Balance at		296,053	309,448
Acquisition		0	0
Impairment		0
Other		(3,215)	(13,395)
Balance at	292,838	292,838	296,053	309,448
International Mailing
Goodwill [Line Items]
Gross value before accumulated impairment						148,351	162,146
Accumulated impairment						0	0
Goodwill	145,566	148,351	162,146	162,146		148,351	162,146
Goodwill [Roll Forward]
Balance at		148,351	162,146
Acquisition		0	0
Impairment		0
Other		(2,785)	(13,795)
Balance at	145,566	145,566	148,351	162,146
Small & Medium Business Solutions
Goodwill [Line Items]
Gross value before accumulated impairment						444,404	471,594
Accumulated impairment						0	0
Goodwill	438,404	444,404	471,594	471,594		444,404	471,594
Goodwill [Roll Forward]
Balance at		444,404	471,594
Acquisition		0	0
Impairment		0
Other		(6,000)	(27,190)
Balance at	438,404	438,404	444,404	471,594
Production Mail
Goodwill [Line Items]
Gross value before accumulated impairment						105,757	110,837
Accumulated impairment						0	0
Goodwill	101,099	105,757	110,837	110,837		105,757	110,837
Goodwill [Roll Forward]
Balance at		105,757	110,837
Acquisition		0	0
Impairment		0
Other		(4,658)	(5,080)
Balance at	101,099	101,099	105,757	110,837
Presort Services
Goodwill [Line Items]
Gross value before accumulated impairment						196,890	195,140
Accumulated impairment						0	0
Goodwill	196,890	196,890	195,140	195,140		196,890	195,140
Goodwill [Roll Forward]
Balance at		196,890	195,140
Acquisition		0	1,750
Impairment		0
Other		0	0
Balance at	196,890	196,890	196,890	195,140
Enterprise Business Solutions
Goodwill [Line Items]
Gross value before accumulated impairment						302,647	305,977
Accumulated impairment						0	0
Goodwill	297,989	302,647	305,977	305,977		302,647	305,977
Goodwill [Roll Forward]
Balance at		302,647	305,977
Acquisition		0	1,750
Impairment		0
Other		(4,658)	(5,080)
Balance at	297,989	297,989	302,647	305,977
Software Solutions
Goodwill [Line Items]
Percentage of fair value in excess of carrying value					15.00%
Gross value before accumulated impairment						674,976	677,008
Accumulated impairment						0	0
Goodwill	501,591	674,976	677,008	677,008		674,976	677,008
Goodwill [Roll Forward]
Balance at		674,976	677,008
Acquisition		11,908	5,792
Impairment		(171,092)
Other		(14,201)	(7,824)
Balance at	501,591	501,591	674,976	677,008
Global Ecommerce
Goodwill [Line Items]
Gross value before accumulated impairment						323,930	23,910
Accumulated impairment						0	0
Goodwill	333,351	323,930	23,910	23,910		323,930	23,910
Goodwill [Roll Forward]
Balance at		323,930	23,910
Acquisition		9,421	300,020
Impairment		0
Other		0	0
Balance at	333,351	333,351	323,930	23,910
Digital Commerce Solutions
Goodwill [Line Items]
Gross value before accumulated impairment						998,906	700,918
Accumulated impairment						0	0
Goodwill	834,942	998,906	700,918	700,918		998,906	700,918
Goodwill [Roll Forward]
Balance at		998,906	700,918
Acquisition		21,329	305,812
Impairment		(171,092)
Other		(14,201)	(7,824)
Balance at	$ 834,942	834,942	998,906	700,918
Other
Goodwill [Line Items]
Gross value before accumulated impairment							194,232
Accumulated impairment							0
Goodwill		0	194,232	194,232		$ 0	$ 194,232
Goodwill [Roll Forward]
Balance at		$ 0	194,232
Acquisition			0
Other			(194,232)
Balance at			$ 0	$ 194,232