Other Assets - Long-Term (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Contract assets, long term	$ 11,667
Prepaid Interest	5,596	$ 5,601
Deposits	616	616
Other noncurrent assets	46	51
Total	$ 17,925	$ 6,268