Quarterly report pursuant to Section 13 or 15(d)

Income Taxes (Details)

v3.10.0.1
Income Taxes (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Dec. 31, 2018
Dec. 31, 2017
Income Tax Disclosure [Abstract]            
Income tax expense $ 70,570 $ 119,513 $ 150,819 $ 233,486    
Income Taxes [Line Items]            
Effective income tax rate percent 19.40% 37.20% 20.60% 36.30%    
Valuation allowance $ 52,405   $ 52,405     $ 52,883
Forecast            
Income Taxes [Line Items]            
Effective income tax rate percent         22.00%