Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2019	Jan. 01, 2018	Dec. 31, 2017	Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liabilities		$ 126,740		$ 126,740
Right-of-use assets		110,880		110,880
Unrealized gain/ (loss) on securities available-for-sale
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to change in accounting principles							$ (339)
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to change in accounting principles	[1]								$ 334
ASU 2016-01 | Unrealized gain/ (loss) on securities available-for-sale
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to change in accounting principles							(339)
ASU 2016-01 | Unrealized gain/ (loss) on securities available-for-sale | Reclassification out of Accumulated Other Comprehensive Income
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to change in accounting principles							(339)
ASU 2016-01 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to change in accounting principles							339
ASU 2016-01 | Retained Earnings | Reclassification out of Accumulated Other Comprehensive Income
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to change in accounting principles							339
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liabilities						$ 124,000
Right-of-use assets						$ 108,000
ASU 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to change in accounting principles		$ 339	$ 145	$ 540	$ 280
ASU 2017-12 | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to change in accounting principles							5
ASU 2017-12 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to change in accounting principles							5
ASU 2017-12 | Retained Earnings | Reclassification out of Accumulated Other Comprehensive Income
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to change in accounting principles							$ (5)
ASU 2018-02 | Reclassification out of Accumulated Other Comprehensive Income
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification due to change in accounting principles								$ 1,500

[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.”