Derivative Instruments - Forward Contracts Outstanding, Estimated Fair Value, Change in Fair Value and Realized Gains of Derivative Instruments (Detail) - Forward Contracts - Call options on equities $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($)
Derivative [Line Items]
Purchase Date	Mar. 01, 2016
Fair Value	$ 6,060
Unrealized gains (losses) in net earnings	$ 560