Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits at beginning of year	$ 2,526	$ 3,219
Decreases relating to positions taken in prior periods	(298)	0
Increases relating to positions taken in prior periods	0	221
Increases relating to current period	1,584	475
Decreases due to settlements with tax authorities	(233)	(1,372)
Decreases due to lapse of statute of limitations	(16)	(17)
Unrecognized tax benefits at end of year	$ 3,563	$ 2,526

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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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 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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