Derivatives Instruments and Hedging Activities - Offsetting Assets and Liabilities (Details) - Pro Forma - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Derivative assets
Gross Amounts of Recognized Assets/ Liabilities	$ 5,264	$ 17,633
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheet	5,264	17,633
Gross Amounts Not Offset in the Consolidated Balance Sheet
Derivative Financial Instruments	(935)	(5,409)
Cash Collateral Received (Pledged)	0	0
Net Amount	4,329	12,224
Derivative liabilities
Gross Amounts of Recognized Assets/ Liabilities	(1,460)	(5,409)
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets/ Liabilities Presented in the Consolidated Balance Sheet	(1,460)	(5,409)
Gross Amounts Not Offset in the Consolidated Balance Sheet
Derivative Financial Instruments	935	5,409
Cash Collateral Received (Pledged)	0	0
Net Amount	$ (525)	$ 0