Income Taxes - Balances of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrecognized tax benefits	$ 40,878	$ 41,110	$ 36,229	$ 35,240
Portion that, if recognized, would reduce tax expense and effective tax rate	40,695	40,977	35,561
Accrued interest on unrecognized tax benefits	6,240	5,459	5,368
Accrued penalties on unrecognized tax benefits	14	631	631
Reasonably possible reduction to the balance of unrecognized tax benefits in succeeding 12 months	6,300
Minimum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible reduction to the balance of unrecognized tax benefits in succeeding 12 months	0	0	0
Portion that, if recognized, would reduce tax expense and effective tax rate	0	0	0
Maximum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible reduction to the balance of unrecognized tax benefits in succeeding 12 months	6,268	9,541	13,655
Portion that, if recognized, would reduce tax expense and effective tax rate	$ 5,693	$ 8,224	$ 12,483