$5.4 million of net realized losses, $4.9 million of which were in the ancillary services and corporate segment and $0.5 million in the title segment, and
$2.4 million of income tax benefits related to previously unrecognized tax credits.
Our accruals for revenues on unreported policies from agencies were not material to our consolidated assets or stockholders’ equity as of December 31, 2016 and 2015. The differences between the amounts our agencies have subsequently reported to us compared to our estimated accruals are substantially offset by any differences arising from prior years’ accruals and have been immaterial to consolidated assets and stockholders’ equity during each of the three prior years. We believe our process provides the most reliable estimate of the unreported revenues on policies and appropriately reflects the trends in agency policy activity.
While we are responsible for assessing whether an impairment of goodwill exists, we utilize inputs from third-party appraisers in performing the quantitative analysis for our impairment review. We evaluate goodwill based on four reporting units with goodwill balances (direct operations, agency operations, international operations and ancillary services). Goodwill is assigned to these reporting units at the time the goodwill is initially recorded. Once assigned to a reporting unit, the goodwill is pooled and no longer attributable to a specific acquisition. All activities within a reporting unit are available to support the carrying value of the goodwill. When a business component within a reporting unit is disposed, goodwill is allocated to the component based on the ratio of the component's fair value over the total fair value of the reporting unit.
Investment income. Investment income increased $2.1 million, or 12.3%, in 2016 compared to 2015 due to increased income from our debt securities, short-term investments, cash equivalents and equity securities as a result of higher invested balances in 2016. Investment income in 2015 was comparable to 2014 due to the slightly higher income from debt securities being offset by reduced income from short-term investments, cash equivalents and equity securities as a result of lower average balances of short term and cash equivalent investments.
Other operating expenses. Other operating expenses include costs that are fixed in nature, costs that follow, to varying degrees, changes in transaction volumes and revenues and costs that fluctuate independently of revenues. Costs that are fixed in nature include attorney and professional fees, third-party-outsourcing provider fees, equipment rental, insurance, rent and other occupancy expenses, repairs and maintenance, technology costs, telephone and title plant expenses. Costs that follow, to varying degrees, changes in transaction volumes and revenues include fee attorney splits, bad debt expenses, ancillary services cost of sales expenses, copy supplies, delivery fees, outside search fees, postage, premium taxes and title plant maintenance expenses. Costs that fluctuate independently of revenues include general supplies, litigation defense, business promotion and marketing and travel.
Our principal sources of cash from operations are premiums on title policies, revenue from title service-related transactions and ancillary services and other operations. Our independent agencies remit cash to us net of their contractual retention. Our principal cash expenditures for operations are employee costs, operating costs and title claims payments.