Basis of Presentation Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Tax Credit Carryforward [Line Items]
Income Tax Expense (Benefit)	$ 12,175	$ 13,500	$ 25,679	$ 27,734
Other Assets
Tax Credit Carryforward [Line Items]
Investments, low income housing	156,800		156,800		$ 155,600
LIH Low Income Housing
Tax Credit Carryforward [Line Items]
Income Tax Expense (Benefit)	$ (2,400)	$ (2,800)	$ (4,800)	$ (5,300)