Offsetting Assets and Liabilities - Offsetting of Assets (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Offsetting Assets [Line Assets]
Gross Amount Of Recognized Assets	$ 10,365,000	$ 669,000
Gross Amount Of Assets Offset In The Balance Sheet	0	0
Net Amount Of Assets Presented In The Balance Sheet	10,365,000	669,000
Gross Amounts Of Financial Instruments Received Not Offset In Balance Sheet	0	0
Gross Amounts Of Cash Collateral Received Not Offset In Balance Sheet	(63,000)	0
Net Amount Of Assets	10,302,000	669,000
Receiver Swaption [Member]
Offsetting Assets [Line Assets]
Gross Amount Of Recognized Assets		669,000
Gross Amount Of Assets Offset In The Balance Sheet		0
Net Amount Of Assets Presented In The Balance Sheet		669,000
Gross Amounts Of Financial Instruments Received Not Offset In Balance Sheet		0
Gross Amounts Of Cash Collateral Received Not Offset In Balance Sheet		0
Net Amount Of Assets		$ 669,000
Interest Rate Swap [Member]
Offsetting Assets [Line Assets]
Gross Amount Of Recognized Assets	10,302,000
Gross Amount Of Assets Offset In The Balance Sheet	0
Net Amount Of Assets Presented In The Balance Sheet	10,302,000
Gross Amounts Of Financial Instruments Received Not Offset In Balance Sheet	0
Gross Amounts Of Cash Collateral Received Not Offset In Balance Sheet	0
Net Amount Of Assets	10,302,000
To Be Announced Contracts [Member]
Offsetting Assets [Line Assets]
Gross Amount Of Recognized Assets	63,000
Gross Amount Of Assets Offset In The Balance Sheet	0
Net Amount Of Assets Presented In The Balance Sheet	63,000
Gross Amounts Of Financial Instruments Received Not Offset In Balance Sheet	0
Gross Amounts Of Cash Collateral Received Not Offset In Balance Sheet	(63,000)
Net Amount Of Assets	$ 0