Accumulated Other Comprehensive Income Reclassification out of AOCI to RE (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2018	Jan. 01, 2017	[1]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 753,954	$ 785,944
Ending Balance	798,211	733,977
Unrealized gain/ (loss) on securities available-for-sale
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(17,556)	(8,140)
Other comprehensive income/ (loss) before reclassifications	22,233	(14,848)
Reclassified from other comprehensive income/ (loss)	0	0
Other comprehensive income/ (loss), net	22,233	(14,848)
Reclassification from the adoption of ASUs 2017-12 and 2016-01			$ (339)
Ending Balance	4,677	(23,327)
Unrealized gain/ (loss) on cash flow hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	391	332
Other comprehensive income/ (loss) before reclassifications	(33)	712
Reclassified from other comprehensive income/ (loss)	(356)	(201)
Other comprehensive income/ (loss), net	(389)	511
Reclassification from the adoption of ASUs 2017-12 and 2016-01			5
Ending Balance	2	848
Unrealized gain/ (loss) on other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(554)	(850)
Other comprehensive income/ (loss) before reclassifications	0	1
Reclassified from other comprehensive income/ (loss)	0	0
Other comprehensive income/ (loss), net	0	1
Reclassification from the adoption of ASUs 2017-12 and 2016-01			0
Ending Balance	(554)	(849)
Accumulated other comprehensive income/ (loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(17,719)	(8,658)
Other comprehensive income/ (loss) before reclassifications	22,200	(14,135)
Reclassified from other comprehensive income/ (loss)	(356)	(201)
Other comprehensive income/ (loss), net	21,844	(14,336)
Reclassification from the adoption of ASUs 2017-12 and 2016-01			$ (334)	$ (334)
Ending Balance	$ 4,125	$ (23,328)

[1] Reclassification due to the adoption of ASU 2016-01 and ASU 2017-12. See Part I. Item 1. “Financial Statements and Supplementary Data - Note 15: Recent Accounting Pronouncements.”