Derivative Instruments and Hedging Activities - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount hedged of borrowed funds using forward starting interest rate swaps	$ 740,000
Amount to be hedged of borrowed funds using forward staring interest rate swaps	$ 400,000
Weighted-average interest rate to be paid	2.53%
Interest rate cash flow hedge to be reclassified during next 12 months, net	$ 1,800
Capital market products income	$ 7,721	$ 8,171	$ 10,024
Portion of fair value outstanding, interest rate swaps covered by collateral agreements (percent)	100.00%	100.00%
Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of variable rate loans hedged using interest rate swaps	$ 1,100,000
Amount hedged of borrowed funds using forward starting interest rate swaps	$ 1,100,000