Genworth Holdings had $534 million and $795 million of cash, cash equivalents and restricted cash as of September 30, 2018 and December 31, 2017, respectively, which included approximately $16 million and $4 million of restricted cash, respectively. Genworth Holdings also held $75 million in U.S. government securities as of September 30, 2018 and December 31, 2017, which included approximately $37 million and $41 million, respectively, of restricted assets.
During the nine months ended September 30, 2018 and 2017, Genworth Holdings received common stock dividends from our international subsidiaries of $169 million and $119 million, respectively. Our U.S. mortgage insurance business also paid a $50 million dividend during the second quarter of 2018. We expect this will be the only dividend paid by our U.S. mortgage insurance business in 2018.
Regulated insurance subsidiaries
The liquidity requirements of our regulated insurance subsidiaries principally relate to the liabilities associated with their various insurance and investment products, operating costs and expenses, the payment of dividends to us, contributions to their subsidiaries, payment of principal and interest on their outstanding debt obligations and income taxes. Liabilities arising from insurance and investment products include the payment of benefits, as well as cash payments in connection with policy surrenders and withdrawals, policy loans and obligations to redeem funding agreements.
Our insurance subsidiaries have used cash flows from operations and investment activities to fund their liquidity requirements. Our insurance subsidiaries’ principal cash inflows from operating activities are derived from premiums, annuity deposits and insurance and investment product fees and other income, including commissions, cost of insurance, mortality, expense and surrender charges, contract underwriting fees, investment management fees and dividends and distributions from their subsidiaries. The principal cash inflows from investment activities result from repayments of principal, investment income and, as necessary, sales of invested assets.
Our insurance subsidiaries maintain investment strategies intended to provide adequate funds to pay benefits without forced sales of investments. Products having liabilities with longer durations, such as certain life insurance and long-term care insurance policies, are matched with investments having similar duration such as long-term fixed maturity securities and commercial mortgage loans. Shorter-term liabilities are matched with fixed maturity securities that have short- and medium-term fixed maturities. In addition, our insurance subsidiaries hold highly liquid, high quality short-term investment securities and other liquid investment grade fixed maturity securities to fund anticipated operating expenses, surrenders and withdrawals. As of September 30, 2018, our total cash, cash equivalents, restricted cash and invested assets were $72.6 billion. Our investments in privately placed fixed maturity securities, commercial mortgage loans, policy loans, limited partnership investments and select mortgage-backed and asset-backed securities are relatively illiquid. These asset classes represented approximately 36% of the carrying value of our total cash, cash equivalents, restricted cash and invested assets as of September 30, 2018.
As of September 30, 2018, our U.S. mortgage insurance business was compliant with the PMIERs capital requirements, with a prudent buffer. Reinsurance transactions provided an aggregate of approximately $575 million of PMIERs capital credit as of September 30, 2018. Our U.S. mortgage insurance business may execute future capital transactions to maintain a prudent level of financial flexibility in excess of the PMIERs capital requirements given the dynamic nature of asset valuations and requirement changes over time, including additional reinsurance transactions and contributions of holding company cash.
In May 2018, Genworth Mortgage Insurance Australia Limited (“Genworth Australia”) announced its intention to commence an on-market share buy-back program for shares up to a maximum aggregate amount of AUD$100 million. Pursuant to the program, Genworth Australia repurchased approximately 36 million of its
171