Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Line Items]
Effective combined Federal and state tax rate	25.40%	15.80%	15.00%	11.50%
Statutory federal tax rate (as a percent)			21.00%
Income Tax Expense (Benefit)	$ 12,221	$ 8,215	$ 22,041	$ 14,564
Increase (decrease) in valuation allowance			(4,200)
Tax expense, reduction of anticipated future benefits	2,200
Deferred Tax Asset Investment In Subsidiary [Member]
Income Tax Disclosure [Line Items]
Income Tax Expense (Benefit)			(4,200)
Increase (decrease) in valuation allowance			(4,200)
Valuation allowance	23,200		$ 23,200
Deferred Tax Asset Foreign Tax Credits [Member]
Income Tax Disclosure [Line Items]
Income Tax Expense (Benefit)	$ 1,900