We maintain office facilities around the world including in North America, Europe (including our principal executive offices in Switzerland), Bermuda, Latin America, Asia Pacific, and the Far East. Most of our office facilities are leased, although we own major facilities in Hamilton, Bermuda and Philadelphia, U.S. Management considers its office facilities suitable and adequate for the current level of operations.
The current accident year P&C combined ratio excluding catastrophe losses was 90.0 percent compared with 92.8 percent in 2012.
We finished the year more diversified in terms of product and geography, increasing our presence in areas such as the U.S., Asia and Latin America that present opportunity for future growth. Net premiums written for personal lines were up in 2013 and we believe our personal lines business is poised to continue its substantial growth globally. Our global reinsurance net premiums written declined slightly in 2013 as we maintained underwriting discipline in an environment of flat-to-declining rates and increasing competition. We do not expect to achieve near-term growth given the soft conditions in the reinsurance market. However, ACE is a substantial buyer of reinsurance and we believe that the softening reinsurance market will benefit ACE in terms of pricing and improved terms that will positively impact our future financial results. While our A&H insurance business grew globally, our Combined Insurance (Combined) business was down for the year. However, for our core Combined business, agent manpower counts in North America and new sales are higher and we expect those factors will translate into net premium growth at Combined in 2014. Looking forward, we expect to have a good year in 2014 as we continue to take advantage of the many growth opportunities we see around the globe including in the U.S.
We have actuarial staff within each of our business units who analyze loss reserves and regularly project estimates of ultimate losses and the corresponding indications of the required IBNR reserve. Note that losses include loss expenses for the purposes of this discussion. We perform an actuarial reserve review for each product line at least once a year. At the conclusion of each review, we establish an actuarial central estimate. The process to select the actuarial central estimate, when more than one
For the 2013 origin year, loss reserves for short-tail lines were typically established for the non-catastrophe exposures using a combination of the initial expected loss ratio method (see above) and loss development methods that incorporate actual loss emergence. As the year progressed, we also adjusted these reserves for non-catastrophe large loss activity that we considered to be greater or less than the assumptions used to establish the initial expected loss ratio. Catastrophe activity was relatively low in 2013 and accordingly the judgments and uncertainties used to establish reserves for incurred catastrophe events were correspondingly less complex. For our short-tail businesses taken as a whole, overall loss trend assumptions did not differ significantly relative to prior years.
Given the long reporting and paid development patterns for workers' compensation business, the development factors used to project actual current losses to ultimate losses for the company's current exposure requires considerable judgment that could be material to consolidated loss and loss expense reserves. Specifically, adjusting ground up ultimate losses by a one percent
Approximately 75 percent of the reserves for this segment are from the crop related lines, which all have short payout patterns, with the majority of the liabilities expected to be resolved in the ensuing twelve months. Reserves for our Multiple Peril Crop Insurance (MPCI) product are set on a case-by-case basis and our aggregate exposure is subject to state level risk sharing formulae. The majority of the development risk arises out of the accuracy of case reserve estimates. We do not view our Agriculture reserves as substantially influenced by the general assumptions and risks underlying more typical P&C reserve estimates.
addition, to support insurance risk, we must prove the reinsurer's risk of loss varies with that of the reinsured and/or support various scenarios under which the assuming entity can recognize a significant loss.
valuation hierarchy. During 2013, 2012 and 2011, we transferred assets of $88 million, $110 million and $70 million, respectively, out of Level 3 assets to other levels of the valuation hierarchy. Refer to Note 4 to the Consolidated Financial Statements for a description of the valuation techniques and inputs used to determine fair values of financial instruments measured or disclosed at fair value by valuation hierarchy (Levels 1, 2, and 3) as well as a roll-forward of Level 3 financial instruments measured at fair value for the years ended December 31, 2013, 2012, and 2011.