Restrictions on Cash and Cash Equivalents	6 Months Ended
	Jun. 30, 2020
Cash and Cash Equivalents [Abstract]
Restrictions on Cash and Cash Equivalents	Restrictions on Cash and Cash EquivalentsThe Bank is required to maintain reserves against its deposit liabilities. Prior to March 2020, reserves were in the form of cash and balances with the FRB. The FRB suspended cash reserve requirements effective March 26, 2020. The amount of such reserves as of December 31, 2019 was $218.9 million. In addition, cash collateral is posted by the Corporation with counterparties to secure derivative and other contracts. The amounts of such cash collateral as of June 30, 2020 and December 31, 2019 were $473.2 million and $199.6 million, respectively.