Cash and Cash Equivalents	12 Months Ended
Cash and Cash Equivalents	Dec. 31, 2015
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents	Cash and Cash Equivalents As of December 31, 2015, cash and cash equivalents include cash due from the FRB of $2.4 billion and cash due from depository institutions of $22.4 million. As of December 31, 2014, cash and cash equivalents include cash due from the FRB of $2.3 billion and cash due from depository institutions of $14.9 million. As of December 31, 2015 and 2014, we had no outstanding cash equivalents. In 2010, the FRB introduced the Term Deposit Facility to facilitate the conduct of monetary policy by providing a tool that may be used to manage the aggregate quantity of reserve balances held by depository institutions. Under this program, the FRB accepts deposits for a stated maturity at a rate of interest determined via auction. The funds are removed from the accounts of participating institutions for the life of the term deposit. We participated in these auctions in 2015 and 2014, resulting in interest income of $0.3 million and $1.2 million, respectively. As of December 31, 2015 and 2014, no funds were on deposit with the FRB under this program. We are required to maintain average reserve balances with the FRB based on a percentage of deposits. The average amounts of those reserves for the years ended December 31, 2015 and 2014 were $1.2 million and $0.3 million, respectively.

The entire disclosure for cash and cash equivalent footnotes, which may include the types of deposits and money market instruments, applicable carrying amounts, restricted amounts and compensating balance arrangements. Cash and equivalents include: (1) currency on hand (2) demand deposits with banks or financial institutions (3) other kinds of accounts that have the general characteristics of demand deposits (4) short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments maturing within three months from the date of acquisition qualify.