Borrowings (Narrative) (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Securities sold under repurchase agreements
Document Period End Date	Dec. 31, 2019
Securities Sold Under Agreements to Repurchase	$ 604,306	$ 504,296
Long-term Repurchase Agreements with Government Entities
Securities sold under repurchase agreements
Securities Sold Under Agreements to Repurchase	$ 2,100	100
Repurchase agreements, Weighted average interest rate (as a percent)	1.09%
Long-term Repurchase Agreements with Private Institutions
Securities sold under repurchase agreements
Securities Sold Under Agreements to Repurchase	$ 600,000	$ 500,000
Repurchase agreements, Weighted average interest rate (as a percent)	2.68%
Repurchase Agreement Counterparty, Weighted Average Maturity of Agreements	4 years
Repurchase Agreement Counterparty, Weighted Average Maturity of Agreements early termination	3 years 4 months 24 days