Securities (Proceeds from Gross Gains on and Gross Losses on Sale of Securities) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Proceeds	$ 268,413	$ 455,162	$ 213,877
Gross losses		$ 25,480

This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

No definition available.

Name:	us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration