Accumulated Other Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Gain (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	$ 1,438,274	$ 1,359,056
Net change	60,773	(31,778)
Balance	2,302,823	1,357,103
Unrealized Gains (Losses) on Securities Available for Sale
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(24,279)	(2,160)
Net change	22,602	(23,401)
Balance	(1,677)	(25,561)
Unrealized Gains (Losses) on Defined Benefit Pension Plans
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(328)	(531)
Balance	(328)	(531)
Unrealized Gains (Losses) on Derivative Instruments Designated as Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(18,305)	(16,342)
Net change	38,171	(8,377)
Balance	19,866	(24,719)
Accumulated OCI
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(42,912)	(19,033)
Net change	60,773	(31,778)
Balance	$ 17,861	$ (50,811)