Supplemental balance sheet and cash flow information (intangibles) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Amortizable intangibles [Abstract]
Gross carrying amount	$ 571,574	$ 549,424
Accumulated amortization	(433,335)	(413,412)
Net carrying amount	138,239	136,012
Total intangibles, gross carrying amount	590,674	568,524
Total intangibles, accumulated amortization	(433,335)	(413,412)
Total intangibles, net carrying amount	157,339	155,112
Total amortization of intangibles	51,796	52,969	45,302
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	55,069	62,232	39,754
Weighted-average amortization period (in years)	6	4	5
Estimated future amortization expense [Abstract]
2012	37,121
2013	26,700
2014	15,027
2015	8,043
2016	5,713
Internal use software [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	33,169	36,442	24,911
Weighted-average amortization period (in years)	4	4	3
Customer lists/relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	12,600	16,690	13,943
Weighted-average amortization period (in years)	8.2	1.0	7
Distributor contracts [Member] | New England Business Service Inc. (NEBS) [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	9
Initial contract term (in years)	5Y
Length of contractual renewal periods (in years)	5Y
Assumed contract retention rate (in hundredths)	90.00%
Average period remaining to next contract renewal (in years)	2.3
Trade names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	8,300	9,100	900
Weighted-average amortization period (in years)	9.5	10	10
Other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,000	0	0
Weighted-average amortization period (in years)	4	0	0
Internal use software [Member]
Amortizable intangibles [Abstract]
Gross carrying amount	410,905	378,269
Accumulated amortization	(345,145)	(314,267)
Net carrying amount	65,760	64,002
Total intangibles, accumulated amortization	(345,145)	(314,267)
Total amortization of intangibles	31,562	29,121	25,152
Customer lists/relationships [Member]
Amortizable intangibles [Abstract]
Gross carrying amount	52,542	72,292
Accumulated amortization	(26,059)	(43,660)
Net carrying amount	26,483	28,632
Total intangibles, accumulated amortization	(26,059)	(43,660)
Distributor contracts [Member]
Amortizable intangibles [Abstract]
Gross carrying amount	30,900	30,900
Accumulated amortization	(28,198)	(26,396)
Net carrying amount	2,702	4,504
Total intangibles, accumulated amortization	(28,198)	(26,396)
Trade names [Member]
Amortizable intangibles [Abstract]
Gross carrying amount	67,661	59,361
Accumulated amortization	(25,958)	(22,009)
Net carrying amount	41,703	37,352
Total intangibles, accumulated amortization	(25,958)	(22,009)
Other [Member]
Amortizable intangibles [Abstract]
Gross carrying amount	9,566	8,602
Accumulated amortization	(7,975)	(7,080)
Net carrying amount	1,591	1,522
Total intangibles, accumulated amortization	$ (7,975)	$ (7,080)