Derivative Financial Instruments - Summary of Outstanding Swaps (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Assets, at Fair Value	$ 12,430,000		$ 10,365,000
Liabilities, at Fair Value	3,633,000		1,982,000
Swap [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	$ 800,000,000
Average Fixed Pay Rate	1.32%
Average Receive Rate	1.07%
Assets, at Fair Value	$ 11,033,000
Average Maturity	3 years 4 months 9 days	3 years 4 months 10 days
Swap [Member] | 1-3 Years
Derivatives, Fair Value [Line Items]
Notional Amount	$ 600,000,000
Average Fixed Pay Rate	1.05%
Average Receive Rate	1.04%
Assets, at Fair Value	$ 12,430,000
Average Maturity	2 years 10 months 10 days
Swap [Member] | 3-5 Years
Derivatives, Fair Value [Line Items]
Notional Amount	$ 200,000,000		$ 700,000,000
Average Fixed Pay Rate	2.14%		1200.00%
Average Receive Rate	1.15%		910.00%
Assets, at Fair Value			$ 9,500,000
Liabilities, at Fair Value	$ (1,397,000)
Average Maturity	4 years 10 months 2 days