Income Taxes - Reconciliation of Effective Income Tax Rate (Details 1)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of the applicable statutory U.S. income tax rate to the effective tax rate
Statutory U.S. federal tax rate	35.00%	35.00%	35.00%
Increase/(decrease) in tax rate resulting from:
U.S. state and local income taxes, net of U.S. federal income tax benefit	2.20%	1.60%	1.60%
Tax-exempt income	(3.10%)	(2.90%)	(2.10%)
Non-U.S. subsidiary earnings	(4.90%)	(2.40%)	(2.30%)
Business tax credits	(5.40%)	(4.20%)	(4.00%)
Nondeductible legal expense	8.00%	(0.20%)	0.90%
Other, net	(1.00%)	(0.50%)	0.00%
Effective tax rate	30.80%	26.40%	29.10%