Segment Information - Selected Segment Financial Data, Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Assets	$ 1,802,186	$ 1,975,788
Americas Segment [Member] | United States [Member]
Segment Reporting Information [Line Items]
Assets	959,488	1,182,309
Americas Segment [Member] | Other [Member]
Segment Reporting Information [Line Items]
Assets	29,495	33,492
EMEA Segment [Member]
Segment Reporting Information [Line Items]
Assets	700,191	643,275
Asia/Pacific Segment [Member]
Segment Reporting Information [Line Items]
Assets	$ 113,012	$ 116,712