Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits
Balance at the beginning of the year	$ 106,162	$ 90,910	$ 66,385
Increases related to current year tax positions	22,649	27,875	26,873
Increases related to prior year tax positions	7,584	1,620	1,191
Decreases related to prior year tax positions	0	(1,075)	(255)
Lapse of the applicable statute of limitations	(18,182)	(13,168)	(3,284)
Balance at the end of the year	$ 118,213	$ 106,162	$ 90,910

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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- Definition

Amount of unrecognized tax benefits.

+ References

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

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