Income Taxes - Reconciliation of Uncertain Tax Positions (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Beginning balance of uncertain tax positions	$ 9,866	$ 10,441
Additions related to current year tax positions	0	0
Reductions related to prior year tax positions	(4)	(506)
Settlements	0	0
Lapse of statute of limitations	(74)	(69)
Ending balance of uncertain tax positions	$ 9,788	$ 9,866

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Amount of unrecognized tax benefits.

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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