Loans Receivable and Allowance for Credit Losses (Summary of Activities in Allowance for loan losses by Portfolio Segments and Unfunded Credit Commitments) (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 01, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses
Accounting Standards Update [Extensible List]	Accounting Standards Update 2016-02		Accounting Standards Update 2016-13		Accounting Standards Update 2016-13
Allowance for unfunded credit reserves
Allowance for Unfunded Credit Commitments		$ 33,500
(Reversal of) provision for credit losses		(35,000)	$ 210,653	$ 98,685
Allowance for Unfunded Credit Commitments		27,500	33,500
Unfunded Loan Commitment
Allowance for unfunded credit reserves
Allowance for Unfunded Credit Commitments	$ 12,566	33,577	11,158	12,566
(Reversal of) provision for credit losses		(6,063)	11,962	(1,408)
Allowance for Unfunded Credit Commitments		$ 27,514	33,577	11,158	$ 12,566
Cumulative Effect, Period of Adoption, Adjustment
Allowance for unfunded credit reserves
Allowance for Unfunded Credit Commitments			$ 10,457
Allowance for Unfunded Credit Commitments				$ 10,457