Loans Receivable and Allowance for Credit Losses (Allowance for Credit Losses Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Losses
Financing receivable and off balance sheet credit loss allowance	$ 569,100	$ 653,600
Decrease in allowance for credit losses	$ (84,500)
Decrease in allowance for credit losses, percent	13.00%
(Reversal of) provision for credit losses	$ (35,000)	$ 210,653	$ 98,685
Commercial and Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses
Decrease in allowance for loan losses	(78,400)
Decrease in allowance for unfunded credit commitments	$ (6,100)