Segment Reporting - Information about Segment Assets by Country (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total assets	$ 3,484,539	$ 3,416,879
AEA [Member]
Segment Reporting Information [Line Items]
Assets, continuing operations	904,004	976,179
MEA [Member]
Segment Reporting Information [Line Items]
Assets, continuing operations	949,155	990,671
ASA [Member]
Segment Reporting Information [Line Items]
Assets, continuing operations	853,246	601,394
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Assets, continuing operations	$ 778,134	$ 848,635