Reconciliation of Cash and Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Cash and cash equivalents presented in the consolidated condensed balance sheets	$ 45,200	$ 39,620	$ 47,152	$ 103,172
Restricted cash	2,504
Cash, cash equivalents and restricted cash presented in the consolidated condensed statements of cash flows	$ 47,704	$ 39,620	$ 47,152	$ 103,172