Other Assets and Other Liabilities Held for Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Other assets held for sale	$ 14,898		$ 165,780
Other liabilities held for sale	$ 1,840		$ 157,366
Heartland
Business Acquisition [Line Items]
Branches and loans acquired		$ 141,000
Deposits and liabilities		$ 154,600