Operating Segments (Detail) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Segment Reporting Information [Line Items]
Revenues before reimbursable items	$ 380,210	$ 362,739	$ 742,854	$ 705,400
Revenue for reportable segment	447,554	430,887	876,985	844,350
Depreciation and amortization	41,967	40,352	83,035	78,870
Operating income	78,529	79,829	151,557	159,541
North America Services
Segment Reporting Information [Line Items]
Revenues before reimbursable items	198,775	202,061	393,365	417,371
Revenue for reportable segment	233,903	236,810	464,461	491,038
Depreciation and amortization	19,926	18,891	39,392	39,294
Operating income	64,068	66,218	119,268	136,006
International Services
Segment Reporting Information [Line Items]
Revenues before reimbursable items	93,778	74,769	181,198	151,050
Revenue for reportable segment	97,670	77,987	188,380	157,379
Depreciation and amortization	11,960	8,597	23,668	17,192
Operating income	10,122	11,673	21,147	22,956
Merchant Services
Segment Reporting Information [Line Items]
Revenues before reimbursable items	93,041	91,889	179,560	148,661
Revenue for reportable segment	123,084	123,906	238,840	211,225
Depreciation and amortization	9,313	12,253	18,460	20,791
Operating income	25,708	23,367	52,631	41,223
Intersegment Elimination
Segment Reporting Information [Line Items]
Revenues before reimbursable items	(5,384)	(5,980)	(11,269)	(11,682)
Revenue for reportable segment	(7,103)	(7,816)	(14,696)	(15,292)
Corporate Administration
Segment Reporting Information [Line Items]
Depreciation and amortization	768	611	1,515	1,593
Operating income	$ (21,369)	$ (21,429)	$ (41,489)	$ (40,644)