Acquisitions and Divestiture (Schedule of Fair Value of Net Assets Acquired Acquired and Liabilities Assumed - FNBC) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jul. 13, 2018	Dec. 31, 2017	Apr. 28, 2017	Mar. 10, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Total Loans		$ 10,400,000
Goodwill	$ 790,972		$ 745,523			$ 621,193
FNBC Transactions [Member]
Business Acquisition [Line Items]
Cash and due from banks			160,788
Interest-bearing time deposits with other banks			382,622
Fed funds sold and other short-term investments			148
Securities			213,877
Total Loans			1,368,669
Property and equipment			20,934
Accrued interest receivable			4,028
Identifiable intangible assets	$ 25,300		25,300
Deferred tax asset			2,220
Other assets			4,213
Total identifiable assets			2,182,799
Deposits			1,928,509
Short-term borrowings			596,635
Long-term debt			93,120
Other liabilities			4,686
Total liabilities			2,622,950
Net identifiable assets acquired (liabilities assumed)			(440,151)
Consideration (Paid) Received			315,821
Goodwill			$ 124,330
FNBC I [Member]
Business Acquisition [Line Items]
Cash and due from banks					$ 2,856
Total Loans					1,203,092
Property and equipment					11,946
Accrued interest receivable					3,143
Identifiable intangible assets					3,900
Deferred tax asset					856
Other assets					63
Total identifiable assets					1,225,856
Deposits					398,171
Short-term borrowings					510,749
Long-term debt					93,120
Other liabilities					1,607
Total liabilities					1,003,647
Net identifiable assets acquired (liabilities assumed)					222,209
Consideration (Paid) Received					(325,756)
Goodwill					$ 103,547
FNBC II [Member]
Business Acquisition [Line Items]
Cash and due from banks				$ 157,932
Interest-bearing time deposits with other banks				382,622
Fed funds sold and other short-term investments				148
Securities				213,877
Total Loans				165,577
Property and equipment				8,988
Accrued interest receivable				885
Identifiable intangible assets				21,400
Deferred tax asset				1,364
Other assets				4,150
Total identifiable assets				956,943
Deposits				1,530,338
Short-term borrowings				85,886
Other liabilities				3,079
Total liabilities				1,619,303
Net identifiable assets acquired (liabilities assumed)				(662,360)
Consideration (Paid) Received				641,577
Goodwill				$ 20,783