Pledged Assets and Collateral - Schedule of Pledged Assets (Details) - USD ($) $ in Billions	Mar. 31, 2019	Dec. 31, 2018
Pledged assets and Collateral
Assets that may be sold or repledged or otherwise used by secured parties	$ 166.9	$ 104.0
Assets that may not be sold or repledged or otherwise used by secured parties	109.9	83.7
Total assets pledged	730.0	663.0
Assets pledged at Federal Reserve banks and FHLBs
Pledged assets and Collateral
Total assets pledged	$ 453.2	$ 475.3