Selected Segment Financial Data, Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Assets	$ 1,533,724	$ 1,250,886
Americas - United States | Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	963,514	635,558
Americas - Other | Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	42,859	26,580
EMEA | Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	368,250	404,016
Asia /Pacific | Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	$ 159,101	$ 184,732