Income Taxes - Deferred (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Classification of deferred tax amounts
Non-current assets	$ 1,208	$ 4,290
Non-current liabilities	19,331	19,520
Deferred tax assets:
Allowances for doubtful accounts	776	820
Deferred branch tax benefit	11,813	11,801
Deferred revenue	109	84
NOL credit and other carryovers	274	204
Fixed assets	94	51
Accrued expenses	1,455	1,123
Foreign tax credit	18,497	14,729
Stock compensation	3,634	3,613
Pension	360	196
Interest rate swap	178
Intangibles	1,354	1,447
Equity method gains and losses	21,976	12,900
Other DTA	38	17
Less: Foreign income valuation allowance	(22,570)	(12,546)
Less: Foreign tax credit valuation allowance	(18,497)	(14,729)
Deferred tax assets, gross	19,491	19,710
Deferred tax liabilities:
Prepaid expenses	(504)	(404)
Intangibles	(15,496)	(15,788)
Interest Rate Swap		(365)
Property and equipment	(8,225)	(6,678)
Amortization expense	(13,389)	(11,705)
Total deferred tax liabilities	(37,614)	(34,940)
Net deferred tax liabilities	$ (18,123)	$ (15,230)