Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2014	Apr. 18, 2014
Business Acquisition [Line Items]
Deferred tax asset, net	$ 149,320	$ 149,320	$ 230,442
Net operating loss carryforwards, valuation allowance	2,600	2,600
Gross unrecognized tax benefits	2,900	$ 2,900
Effective income tax rate on unrecognized tax benefits that would impact effective tax rate		0.70%
Recognized benefit in interest	21	$ 4
Accrued interest related to unrecognized tax benefits	$ 395	$ 395
Sterling Financial Corporation [Member]
Business Acquisition [Line Items]
Deferred tax asset, net				$ 276,800
Net operating loss and tax credit carryforwards				$ 238,400