Income Taxes Income Taxes - Income Tax Reconciliation (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
United States statutory rate	35.00%	35.00%	35.00%
State and local taxes	0.10%	0.20%	0.13%
Foreign tax rate differential	(2.60%)	(3.70%)	(2.90%)
Other items, net	(1.20%)	0.00%	(0.70%)
Total effective tax rate	31.30%	31.50%	31.50%