Borrowings

Borrowed funds at December 31, 2018 and 2017 are summarized as follows:



	December 31,
	2018		2017		2018		2017
	Balance				Weighted average interest rate
	(In thousands)

Overnight lines of credit	$	159,600	$	46,000	2.60	%	1.53	%
Federal Home Loan Bank advances	1,029,580		822,400		2.40		1.92
Junior subordinated debt	—		50,657		—		8.00
Securities sold under agreements to repurchase	—		10,000		—		3.23
	$	1,189,180	$	929,057	2.43	%	2.25	%

At December 31, 2018 and 2017, the Company had outstanding overnight lines of credit with the Federal Home Loan Bank of $159.6 million and $46.0 million, respectively. Interest expense on the overnight advances for the years ended December 31, 2018, September 30, 2017 and 2016, and the three months ended December 31, 2017, were $2.2 million, $233,000, $42,000, and $70,000 respectively.

(9) Borrowings (continued)

At December 31, 2018, the Bank could borrow funds from the FHLB under an overnight advance program up to the Bank's maximum borrowing capacity based on its ability to collateralize such borrowings. Members in good standing can borrow up to 50% of their asset size as long as they have qualifying collateral to support the advance and purchase of FHLB capital. Additionally, at both December 31, 2018 and 2017, the Bank had unused correspondent bank lines of credit with an aggregate overnight borrowing capacity of $225.0 million.

At December 31, 2018 FHLB advances were at fixed rates with maturities between January 2019 and December 2022, and at December 31, 2017, FHLB advances were at fixed rates with maturities between January 2018 and September 2021. At December 31, 2018 and 2017, FHLB advances were collateralized by FHLB capital stock owned by the Bank and loans with carrying values totaling $1.7 billion and $1.6 billion, respectively. Loans securing advances consists of one-to-four family, multifamily, commercial and home equity real estate loans. Interest expense on FHLB advances for the years ended December 31, 2018, September 30, 2017 and 2016, and the three months ended December 31, 2017 were $17.1 million, $12.8 million, $13.2 million, and $3.3 million respectively.

At December 31, 2018 and 2017, FHLB advances totaling $320.0 million and $20.0 million, respectively, were outstanding in association with an interest rate swap program. See note 19 for information regarding these transactions.

Scheduled maturities of FHLB advances including lines of credit at December 31, 2018 are summarized as follows:



	Year Ended December 31,
	2018
	(In thousands)

One year or less	$	761,900
After one year to two years	229,045
After two years to three years	155,010
After three years to four years	43,225
After four years	—
Total FHLB advances	$	1,189,180

At December 31, 2018 and 2017, the junior subordinated debt balances were $0 and $50.7 million, respectively. In August 2018, the Company redeemed all junior subordinated debt securities. The carrying value as of December 31, 2017 included deferred issuance costs of $890,000. Interest expense for the year ended December 31, 2018 was $3.5 million. Interest expense for both the years ended September 30, 2017 and 2016 was $4.2 million, while interest expense for the three months ended December 31, 2017 was $1.0 million.

At December 31, 2018 and 2017, the balance of securities sold under agreements to repurchase were $0 and $10.0 million, respectively. Interest expense on securities sold under agreements to repurchase for the years ended December 31, 2018, September 30, 2017 and 2016, and the three months ended December 31, 2017 were $3,000, $1.6 million, $2.4 million, and $203,000 respectively. As of December 31, 2018 and 2017, securities available for sale with a carrying value of $0 and $12.9 million, respectively, were pledged to secure these borrowings.