Quarterly Results Quarterly Results (Unaudited) - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effect of Fourth Quarter Events [Line Items]
Net foreign currency gain			$ 7,955	$ 7,820	$ 1,517
Egypt, Pounds
Effect of Fourth Quarter Events [Line Items]
Net foreign currency gain	$ 6,000
Recovery of Legal and Related Fees
Effect of Fourth Quarter Events [Line Items]
Other		$ 6,000