Income Taxes (Reconciliation of Effective Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Expected tax rate	7.80%	7.80%	7.80%
Income not subject to income tax	(10.70%)	(14.20%)	(7.10%)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent	4.40%	14.50%	2.30%
Foreign taxes at local expected tax rates	(4.60%)	(1.70%)	4.40%
Disallowed expenses and capital allowances	0.40%	3.20%	0.20%
Prior year refunds and adjustments	(0.30%)	0.00%	1.20%
Other	(0.70%)	(3.20%)	(2.90%)
Effective tax rate	(3.70%)	6.40%	5.90%