Annual report pursuant to Section 13 and 15(d)

Income Taxes (Narrative) (Details)

v3.8.0.1
Income Taxes (Narrative) (Details) - USD ($)
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Operating Loss Carryforwards [Line Items]      
Tax Cuts and Jobs Act Of 2017, provisional tax expense $ 95,610,000    
Tax Cuts and Jobs Act of 2017, provisional decrease to deferred tax assets 15,017,000    
Tax Cuts and Jobs Act of 2017, deferred income tax expense resulting from remeasurement of deferred tax asset 15,017,000    
Tax Cuts and Jobs Act Of 2017, provisional transition tax obligation 49,947,000    
Tax Cuts and Jobs Act Of 2017, provisional liability for withholding tax 23,690,000    
Tax Cuts and Jobs Act of 2017, foreign tax credit 6,956,000    
Net operating loss carryforwards 72,297,000    
Net operating loss carryforwards, not subject to expiration 59,943,000    
Net operating loss carryforwards, subject to expiration 15,354,000    
Deferred tax assets, net operating loss carryforwards 20,085,000 $ 3,637,000  
Deferred tax assets, valuation allowance 16,152,000 1,060,000  
Undistributed earnings of foreign subsidiaries 422,940,000    
Change in unrecognized tax benefit reasonably possible, low range 0    
Change in unrecognized tax benefit reasonably possible, high range 2,066,000    
Unrecognized tax benefits that would affect the effective tax rate 6,892,000 7,723,000  
Interest expense and penalties recognized (reversed) 1,402,000 637,000 $ 356,000
Accrued interest and penalties related to uncertain tax positions $ 1,640,000 $ 3,042,000  
Minimum [Member]      
Operating Loss Carryforwards [Line Items]      
Net operating loss carryforwards, expiration year Jan. 01, 2025    
Maximum [Member]      
Operating Loss Carryforwards [Line Items]      
Net operating loss carryforwards, expiration year Jan. 01, 2027