Loans and Allowance for Credit Losses - Industry Classification System (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Lessors of nonresidential buildings
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Principal Balances	$ 3,553,989
Unfunded Commitments	1,053,464
Total exposure	4,607,453	$ 4,442,712
Lessors of residential buildings
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Principal Balances	1,348,050
Unfunded Commitments	814,962
Total exposure	2,163,012	2,126,246
Hotels (except Casino Hotels) and Motels
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Principal Balances	988,712
Unfunded Commitments	71,837
Total exposure	1,060,549	1,039,259
New Housing For-Sale Builders
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Principal Balances	489,417
Unfunded Commitments	747,732
Total exposure	$ 1,237,149	$ 1,124,302