Derivative Instruments and Hedging Activities - Schedule of Gross Amounts of Derivative Assets and Derivative Liabilities (Details) - Not Designated as Hedging Instruments - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
Other Assets
Derivatives (included in Other Assets)
Gross amounts recognized		$ 12,236	$ 8,733
Gross amounts offset		(1,591)	(3,229)
Net Amounts Presented in the Consolidated Balance Sheets		10,645	5,504
Gross amounts not offset	[1]	0	(160)
Net Amount		10,645	5,344
Other Liabilities
Derivatives (included in Other Liabilities)
Gross amounts recognized		12,193	8,569
Gross amounts offset		(1,591)	(3,229)
Net Amounts Presented in the Consolidated Balance Sheets		10,602	5,340
Gross amounts not offset	[1]	(10,053)	0
Net Amount		$ 549	$ 5,340

[1] Amounts represent collateral received/posted for the periods presented.