Segment Reporting - Information about Unconsolidated Affiliates (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Other Significant Reconciling Item [Line Items]
Equity in Loss of Unconsolidated Affiliates	$ (21,486)	$ (7,848)	$ (16,116)
Investments in Unconsolidated Affiliates	26,551	38,186	26,000
Operating Segments [Member] | AEA [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Equity in Loss of Unconsolidated Affiliates	(6,255)	4,829	(4,275)
Investments in Unconsolidated Affiliates	1,540	1,598
Operating Segments [Member] | MEA [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Equity in Loss of Unconsolidated Affiliates	(94)	(2,668)	(1,103)
Operating Segments [Member] | ASA [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Equity in Loss of Unconsolidated Affiliates	(15,137)	(10,009)	$ (10,738)
Investments in Unconsolidated Affiliates	24,327	35,722
Corporate [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Investments in Unconsolidated Affiliates	$ 684	$ 866