Short-term Borrowings	12 Months Ended
Dec. 31, 2017
Debt Disclosure [Abstract]
Short-term borrowings	Note (13)—Short-term borrowings: The Bank currently has available from correspondent banks borrowings capacity in the form of federal fund purchases. The line with First Tennessee Bank, N.A. is for $30,000 as of December 31, 2017 and 2016 and the line with BBVA Compass Bank is for $10,000 as of December 31, 2017 and 2016. Each of these lines may be drawn for fourteen consecutive days. As of December 31, 2017 and 2016 there were no borrowings against these lines. The line with SunTrust Bank is for $15,000 and may be drawn for seven consecutive days before collateral is required. Borrowings that exceed seven days must be secured by a marketable security with a current value of at least 125% of the outstanding balance. As of December 31, 2017 and 2016, there were no borrowings against this line. The line with First National Banker’s Bank is for $10,000 and may be drawn for thirty days before collateral is required. The line with Zions Bank is for $25,000. The line with PNC Bank is for $20,000. The line with ServisFirst Bank is for $15,000. As of December 31, 2017 and 2016, there were no borrowings against these lines. The line with Federal Home Loan Bank is for $300,000 as of December 31, 2017 and 2016, respectively, and is secured by qualifying mortgage loans and investment securities. At December 31, 2017 and 2016, the Company had pledged investments securities of $0 and $60,371 and loans of $968,567 and $565,718, securing borrowings against this line of $190,000 and $150,000 as of December 31, 2017 and 2016, respectively. The Company maintained a line with the Federal Reserve Bank through the Borrower-in-Custody program in 2017 and 2016. As of December 31, 2017 and 2016, $737,856 and $1,072,118 of qualifying loans and $13,544 and $0 of investment securities were pledged to the Federal Reserve Bank through the Borrower-in-Custody program securing a line of credit of $529,547 and $765,107.

Note (13)—Short-term borrowings:

The Bank currently has available from correspondent banks borrowings capacity in the form of federal fund purchases. The line with First Tennessee Bank, N.A. is for $30,000 as of December 31, 2017 and 2016 and the line with BBVA Compass Bank is for $10,000 as of December 31, 2017 and 2016. Each of these lines may be drawn for fourteen consecutive days. As of December 31, 2017 and 2016 there were no borrowings against these lines.

The line with SunTrust Bank is for $15,000 and may be drawn for seven consecutive days before collateral is required. Borrowings that exceed seven days must be secured by a marketable security with a current value of at least 125% of the outstanding balance. As of December 31, 2017 and 2016, there were no borrowings against this line.

The line with First National Banker’s Bank is for $10,000 and may be drawn for thirty days before collateral is required. The line with Zions Bank is for $25,000. The line with PNC Bank is for $20,000. The line with ServisFirst Bank is for $15,000. As of December 31, 2017 and 2016, there were no borrowings against these lines.

The line with Federal Home Loan Bank is for $300,000 as of December 31, 2017 and 2016, respectively, and is secured by qualifying mortgage loans and investment securities. At December 31, 2017 and 2016, the Company had pledged investments securities of $0 and $60,371 and loans of $968,567 and $565,718, securing borrowings against this line of $190,000 and $150,000 as of December 31, 2017 and 2016, respectively.

The Company maintained a line with the Federal Reserve Bank through the Borrower-in-Custody program in 2017 and 2016. As of December 31, 2017 and 2016, $737,856 and $1,072,118 of qualifying loans and $13,544 and $0 of investment securities were pledged to the Federal Reserve Bank through the Borrower-in-Custody program securing a line of credit of $529,547 and $765,107.