Segment Information - Selected Segment Financial Data, Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Assets	$ 1,744,664	$ 1,850,700
Americas - United States [Member]
Segment Reporting Information [Line Items]
Assets	1,138,127	1,210,674
Americas - Other [Member]
Segment Reporting Information [Line Items]
Assets	28,885	32,594
EMEA [Member]
Segment Reporting Information [Line Items]
Assets	465,036	487,629
Asia/Pacific [Member]
Segment Reporting Information [Line Items]
Assets	$ 112,616	$ 119,803