BORROWINGS (Short-Term Borrowings) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Short-term Debt [Line Items]
Other Short-term Borrowings	$ 180,000	$ 70,000
Federal Home Loan Bank of Indianapolis Notes, 0.89%, Due June 28, 2017
Short-term Debt [Line Items]
Other Short-term Borrowings	180,000	0
Federal Home Loan Bank of Indianapolis Notes, 0.58%, Due June 28, 2016
Short-term Debt [Line Items]
Other Short-term Borrowings	$ 0	$ 70,000