Quarterly report pursuant to Section 13 or 15(d)

Income Taxes (Details)

v3.7.0.1
Income Taxes (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Income Tax Disclosure [Abstract]        
Income tax expense $ 113,973 $ 108,242    
Income Taxes [Line Items]        
Effective income tax rate percent 35.50% 38.60%    
Valuation allowance $ 44,022     $ 47,682
Forecast        
Income Taxes [Line Items]        
Effective income tax rate percent     37.30%