Income Taxes (Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Abstract]
Statutory federal expense (benefit)	$ 40,912	$ 30,555	$ (58,307)
Foreign tax rate differential	3,745	1,083	3,534
State and local tax expense (benefit)	5,415	3,941	(230)
REIT adjustment	(34,346)	205,317
Permanent differences	(1,365)	(3,577)	4,892
Tax Act impact on deferred taxes	31,547
Foreign exchange rate changes	(55)	(5,822)	9,212
Other	(1,009)	1,753	3,200
Valuation allowance	(31,607)	(222,185)	46,760
Total provision for income taxes	$ 13,237	$ 11,065	$ 9,061