Corporate Borrowings and Capital Lease Obligations - Offsetting Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Gross Amounts of Recognized Assets (Liabilities) [Member]
Offsetting Assets and Liabilities [Line Items]
Investment in bonds	$ 7,000	$ 7,000
Capital lease obligation	(7,000)	(7,000)
Gross Amounts offset in the Balance Sheet [Member]
Offsetting Assets and Liabilities [Line Items]
Investment in bonds	7,000	7,000
Capital lease obligation	(7,000)	(7,000)
Net Amounts of Assets (Liabilities) presented in the Balance Sheet [Member]
Offsetting Assets and Liabilities [Line Items]
Investment in bonds	0	0
Capital lease obligation	$ 0	$ 0