Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Balance prior to reclassification, consumer, home equity		$ 1,600,000
Balance prior to reclassification, consumer, mortgage		4,472,800
Residential mortgage	$ 5,783,267	5,056,891
Home equity	1,005,802	1,051,927
Market valuation adjustment	155	0
Other real estate owned	$ 15,000	$ 17,000
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average lives of finite-lived intangible assets	10 years
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average lives of finite-lived intangible assets	12 years	14 years