Impact of Accounting Changes (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets	$ 53,167	$ 42,338
Other liabilities	54,094	$ 52,708
Anticipated impact | ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets	25,000
Other liabilities	$ 25,000