FHLB Borrowings (Details) - Schedule of components of FHLB borrowings and weighted average interest rates - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
By type of borrowing:
FHLB borrowings (in Dollars)	$ 695,032	$ 670,077
Weighted average interest rates	2.07%	1.76%
By remaining period to maturity:
Less than 1 year (in Dollars)	$ 525,032	$ 505,077
Less than 1 year	1.98%	1.59%
1 year through less than 2 years (in Dollars)	$ 50,000	$ 35,000
1 year through less than 2 years	1.66%	1.60%
2 years through less than 3 years (in Dollars)	$ 75,000	$ 85,000
2 years through less than 3 years	2.92%	2.65%
3 years through less than 4 years (in Dollars)	$ 45,000	$ 45,000
3 years through less than 4 years	2.15%	2.15%
4 years through 5 years (in Dollars)
4 years through 5 years