Geographic Information for Long-Lived Assets and Revenues in United States and other Countries (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Revenues	$ 29,058	$ 20,241	$ 20,651	$ 33,102	$ 56,768	$ 75,807	$ 73,752	$ 73,747	$ 103,051	$ 279,574	$ 648,325
Reportable Geographical Components [Member]
Long-lived assets:
Long-lived assets	499,615				543,838				499,615	543,838	579,161
Revenues:
Revenues									103,051	279,574	648,325
Reportable Geographical Components [Member] | UNITED STATES
Long-lived assets:
Long-lived assets	489,374				531,518				489,374	531,518	561,109
Revenues:
Revenues									67,609	199,187	491,004
Reportable Geographical Components [Member] | International
Long-lived assets:
Long-lived assets	$ 10,241				$ 12,320				10,241	12,320	18,052
Reportable Geographical Components [Member] | CANADA
Revenues:
Revenues									7,460	33,614	73,092
Reportable Geographical Components [Member] | Other International
Revenues:
Revenues									$ 27,982	$ 46,773	$ 84,229