Fair Value Measurements - Schedule of Fair Values of Financial Assets and Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financial assets:
Cash equivalents	$ 17	$ 55,634
Derivative financial instruments	2,370	618
Total financial assets	2,387	56,252
Level 1 [Member]
Financial assets:
Cash equivalents	17	55,634
Total financial assets	17	55,634
Level 2 [Member]
Financial assets:
Derivative financial instruments	2,370	618
Total financial assets	$ 2,370	$ 618