ACQUISITIONS, Estimated Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands				6 Months Ended
		Jan. 02, 2019	Apr. 02, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Consideration paid [Abstract]
Cash				$ 1,200	$ 1,737
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Goodwill				$ 733,503	$ 733,479	$ 733,503
Wealth Resources Network, Inc [Member]
Consideration paid [Abstract]
Cash		$ 1,200
Total net consideration paid		1,200
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents		0
Premises and equipment		0
Other assets		0
Other liabilities		0
Total identifiable assets, net		1,200
Goodwill		0
Wealth Resources Network, Inc [Member] | Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles		$ 1,200
Other [Member]
Consideration paid [Abstract]
Cash	[1]		$ 1,753
Total net consideration paid	[1]		1,753
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents	[1]		16
Premises and equipment	[1]		10
Other assets	[1]		105
Other liabilities	[1]		(31)
Total identifiable assets, net	[1]		1,443
Goodwill	[1]		310
Other [Member] | Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles	[1]		$ 1,343

[1] Includes amounts related to the Styles Bridges, Penna, and HR Consultants acquisitions.