Acquisitions (Schedule of Fair Value of Net Assets Acquired) (Details) - USD ($) $ in Thousands			6 Months Ended
	Apr. 28, 2017	Mar. 10, 2017	Jun. 30, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill			$ 740,265	$ 621,193
FNBC Transaction [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			1,377,100
Property and equipment			12,337
Accrued interest receivable			3,854
Identifiable intangible assets			24,400
Other assets			4,160
Total identifiable assets			2,179,286
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)			(443,664)
Cash (paid) received			314,871
Unsettled net consideration receivable from FDIC			9,721
Total consideration			324,592
Goodwill			$ 119,072
FNBC I [Member]
Business Acquisition [Line Items]
Cash and due from banks		$ 2,856
Total Loans		1,211,523
Property and equipment		11,837
Accrued interest receivable		2,969
Identifiable intangible assets		3,900
Other assets		63
Total identifiable assets		1,233,148
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)		229,501
Cash (paid) received		(325,564)
Total consideration		(325,564)
Goodwill		$ 96,063
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	500
Accrued interest receivable	885
Identifiable intangible assets	20,500
Other assets	4,097
Total identifiable assets	946,138
Deposits	1,530,338
Short-term borrowings	85,886
Other liabilities	3,079
Total liabilities	1,619,303
Net identifiable assets acquired (liabilities assumed)	(673,165)
Cash (paid) received	640,435
Unsettled net consideration receivable from FDIC	9,721
Total consideration	650,156
Goodwill	$ 23,009