Operating Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Revenues before reimbursable items	$ 398,692	$ 380,210	$ 793,870	$ 742,854
Revenue for reportable segment	462,651	447,554	923,813	876,985
Depreciation and amortization	43,213	41,967	84,086	83,035
Operating income	92,096	78,529	176,927	151,557
Total assets	1,936,541		1,936,541		1,858,392
North America Services
Segment Reporting Information [Line Items]
Revenues before reimbursable items	205,565	198,775	409,614	393,365
Revenue for reportable segment	239,557	233,903	480,156	464,461
Depreciation and amortization	18,821	19,926	37,275	39,392
Operating income	72,060	64,068	140,232	119,268
Total assets	1,704,042		1,704,042		1,621,664
International Services
Segment Reporting Information [Line Items]
Revenues before reimbursable items	99,047	93,778	195,538	181,198
Revenue for reportable segment	103,415	97,670	203,775	188,380
Depreciation and amortization	15,006	11,960	27,917	23,668
Operating income	9,438	10,122	13,552	21,147
Total assets	448,098		448,098		433,203
Merchant Services
Segment Reporting Information [Line Items]
Revenues before reimbursable items	97,701	93,041	196,056	179,560
Revenue for reportable segment	124,903	123,084	250,420	238,840
Depreciation and amortization	8,668	9,313	17,453	18,460
Operating income	32,950	25,708	67,169	52,631
Total assets	486,444		486,444		487,858
Intersegment Elimination
Segment Reporting Information [Line Items]
Revenues before reimbursable items	(3,621)	(5,384)	(7,338)	(11,269)
Revenue for reportable segment	(5,224)	(7,103)	(10,538)	(14,696)
Total assets	(702,043)		(702,043)		(684,333)
Corporate Administration
Segment Reporting Information [Line Items]
Depreciation and amortization	718	768	1,441	1,515
Operating income	$ (22,352)	$ (21,369)	$ (44,026)	$ (41,489)