Income Taxes (Detail Textuals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Tax Cuts and Jobs Act of 2017 (the "Act"), provisional amount related to the remeasurement of certain deferred tax assets and liabilities		$ (22,300)
Tax Cuts and Jobs Act of 2017 (the "Act"), one-time transition tax on the mandatory deemed repatriation of foreign earnings	$ (200)	(200)
Tax Cuts and Jobs Act of 2017 (the "Act"), cumulative foreign earnings		32,400
Earnings exempted associated with foreign subsidiary	20,900
Income tax examination, Increase (decrease) in liability from prior year	34,600	29,600
Unrecognized tax benefits net of offsetting assets	119,000	148,600
Liability related to uncertain tax position inclusive interest and penalties	153,600	178,200
Net acquired uncertain tax position	5,200
Anticipated payment of tax liabilities related to interest and penalty accrual	3,700	4,000
Unrecognized tax benefits arising from U.S. Federal and state tax	12,100
Income tax expense (benefit)	$ (24,344)	$ (44,921)	$ 15,131
United Kingdom
Income Taxes [Line Items]
Effective income tax rate	19.00%	19.25%	20.00%
Foreign Subsidiaries
Income Taxes [Line Items]
Deferred tax liability	$ 8,700
2017
Income Taxes [Line Items]
Effective income tax rate	35.00%
2018
Income Taxes [Line Items]
Effective income tax rate	21.00%