Federal Home Loan Bank Advances (Summary of Outstanding FHLB Advances) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 426,326	$ 559,663
1.44% advance due January 2018
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 0	250,000
Interest rate	1.44%
1.49% advance due February 2018
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 0	94,663
Interest rate	1.49%
1.57% advance due June 2019
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 1,991	0
Interest rate	1.57%
1.75% advance due June 2020
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 3,940	0
Interest rate	1.75%
1.72% advance due June 2020
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 2,461	0
Interest rate	1.72%
1.88% advance due June 2021
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 2,934	0
Interest rate	1.88%
4.18% advance due February 2022
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 25,000	25,000
Interest rate	4.18%
1.52% advance due March 2022
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 50,000	50,000
Interest rate	1.52%
1.45% advance due May 2022
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 50,000	50,000
Interest rate	1.45%
1.46% advance due May 2022
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 90,000	90,000
Interest rate	1.46%
1.98% advance due January 2023
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 100,000	0
Interest rate	1.98%
0.93% advance due January 2028
Federal Home Loan Bank, Advances, Branch Of FHLB Bank [Line Items]
Federal Home Loan Bank advances	$ 100,000	$ 0
Interest rate	0.93%