Income Taxes - Unrecognized Tax Position Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns
Balance as of January 1,	$ 18,951	$ 14,519	$ 12,054
Increase for tax positions taken during the prior period	197	2,620	252
Decrease for settlements with taxing authorities	(126)	(157)	(788)
(Decrease) increase for tax positions taken during the current period	(96)
(Decrease) increase for tax positions taken during the current period		300	107
Currency translation	(318)	(707)
Currency translation			1,626
Balance at period end - unrecognized tax benefit	18,607	16,575	13,251
Accrued interest and penalties	1,627	2,376	1,268
Ending balance	$ 20,234	$ 18,951	$ 14,519

Amount recognized for uncertainty in income taxes classified as noncurrent.

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

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Amount of unrecognized tax benefits.

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Amount of decrease 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 foreign currency translation.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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