Supplemental balance sheet information (goodwill) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	1 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013 VerticalResponse, Inc. [Member]	Sep. 30, 2013 VerticalResponse, Inc. [Member]	Aug. 31, 2013 Acton Marketing, LLC [Member]	Sep. 30, 2013 Acton Marketing, LLC [Member]	Sep. 30, 2013 Small Business Services [Member]	Sep. 30, 2013 Small Business Services [Member] VerticalResponse, Inc. [Member]	Sep. 30, 2013 Financial Services [Member]	Sep. 30, 2013 Financial Services [Member] Acton Marketing, LLC [Member]	Sep. 30, 2013 Direct Checks [Member]
Goodwill [Roll Forward]
Goodwill, gross, beginning of year	$ 809,636					$ 633,952		$ 27,178		$ 148,506
Accumulated impairment charges, beginning of year	(20,000)					(20,000)		0		0
Goodwill, net of accumulated impairment charges, beginning of year	789,636					613,952		27,178		148,506
Goodwill acquired during period (Note 6)		18,735	18,735	1,459	1,459		18,735		1,459
Currency translation adjustment	(76)					(76)		0		0
Goodwill, gross, end of period	829,754					652,611		28,637		148,506
Accumulated impairment charges, end of period	(20,000)					(20,000)		0		0
Goodwill, net of accumulated impairment charges, end of period	$ 809,754					$ 632,611		$ 28,637		$ 148,506