BORROWED FUNDS - Summary of Borrowed Funds (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Short-term borrowings
Principal	$ 659,206	$ 394,480
Weighted Average Rate	1.29%	0.93%
Long-term borrowings
Principal	$ 255,878	$ 142,116
Weighted Average Rate	2.14%	1.69%
Total borrowings	$ 915,084	$ 536,596
Weighted Average Rate	1.53%	1.13%
Advances from the FHLBB
Short-term borrowings
Principal	$ 624,032	$ 372,700
Weighted Average Rate	1.34%	0.97%
Long-term borrowings
Principal	$ 212,815	$ 137,116
Weighted Average Rate	1.45%	1.59%
Other borrowings
Short-term borrowings
Principal	$ 35,174	$ 21,780
Weighted Average Rate	0.51%	0.29%
Subordinated borrowings
Long-term borrowings
Principal	$ 38,063	$ 0
Weighted Average Rate	5.66%	0.00%
Junior subordinated borrowings
Long-term borrowings
Principal	$ 5,000	$ 5,000
Weighted Average Rate	4.69%	4.41%

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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