Commitments and contingencies:

Some financial instruments, such as loan commitments, credit lines, letters of credit, and overdraft protection, are issued to meet customer financing needs. These are agreements to provide credit or to support the credit of others, as long as conditions established in the contract are met, and usually have expiration dates.

Commitments may expire without being used. Off-balance sheet risk to credit loss exists up to the face amount of these instruments, although material losses are not anticipated. The same credit policies are used to make such commitments as are used for loans, including obtaining collateral at exercise of the commitment.



	December 31,
	2018		2017
Commitments to extend credit, excluding interest rate lock commitments	$	1,032,390	$	977,276
Letters of credit	19,024		22,882
Balance at end of period	$	1,051,414	$	1,000,158

Commitments under non-cancelable operating leases were as follows, before considering renewal options that generally are present:



2019	$	4,328
2020	3,780
2021	3,548
2022	2,542
2023	1,613
Thereafter	6,250
Total	$	22,061

Rent expense for the years ended December 31, 2018, 2017 and 2016, was $4,940, $4,245 and $3,904, respectively.

In connection with the sale of mortgage loans to third party investors, the Bank makes usual and customary representations and warranties as to the propriety of its origination activities. Occasionally, the investors require the Bank to repurchase loans sold to them under the terms of the warranties. When this happens, the loans are recorded at fair value with a corresponding charge to a valuation reserve. The total principal amount of loans repurchased (or indemnified for) was $6,646 and $4,704 and $8,326 for the years ended December 31, 2018, 2017 and 2016, respectively. The Company has established a reserve associated with loan repurchases. This reserve is recorded in accrued expenses and other liabilities on the consolidated balance sheets.

The following table summarizes the activity in the repurchase reserve:



	For the year ended December 31,
	2018			2017			2016
Balance at beginning of period	$	3,386		$	2,659		$	2,156
Provision for loan repurchases or indemnifications	174			810			512
Recoveries on previous losses	3			—			9
Losses on loans repurchased or indemnified	(290		)	(83		)	(18		)
Balance at end of period	$	3,273		$	3,386		$	2,659