9.	Commitments and Contingencies

Contractual commitments

Our commitments include obligations under operating leases, which expire through 2020. We have lease commitments for office space in Bellevue, Washington; Taipei, Taiwan; Trowbridge, UK; and Tokyo, Japan. We also lease office space on a month-to-month basis in Akron, Ohio, and on an annual basis in Boston, Massachusetts.

Rent expense was approximately $1.0 million in each of 2017 and 2016.

We had $250,000 pledged as collateral for a bank letter of credit under the terms of our headquarters facility lease. The pledged cash supporting the outstanding letter of credit was recorded as restricted cash equivalents. In September 2016, this letter of credit agreement was replaced by a letter of credit secured by our credit agreement and the corresponding restricted cash equivalents were returned to us.

Operating lease commitments are as follows (in thousands):

2018	$	1,173
2019		1,038
2020		437
Total	$	2,648

Loss contingencies

From time to time, we are subject to legal proceedings, claims, and litigation arising in the ordinary course of business including tax assessments. We defend ourselves vigorously against any such claims. When (i) it is probable that an asset has been impaired or a liability has been incurred and (ii) the amount of the loss can be reasonably estimated, we record the estimated loss. We provide disclosure in the notes to the consolidated financial statements for loss contingencies that do not meet both of these conditions if there is a reasonable possibility that a loss may have been incurred that would be material to the financial statements. Significant judgment is required to determine the probability that a liability has been incurred and whether such liability is reasonably estimable. We base accruals made on the best information available at the time, which can be highly subjective. The final outcome of these matters could vary significantly from the amounts included in the accompanying consolidated financial statements.