|ENVISION HEALTHCARE CORP filed this Form 10-Q on 08/08/2017|
and individuals. We bill for services as delivered, usually within a few days following the date the service is rendered for our ambulatory services segment and within 5 to 30 days following the date the service is rendered for our physician services segment. Generally, unpaid amounts that are 30 to 45 days past due are rebilled based on a standard set of procedures. If amounts remain uncollected after 60 days, we proceed with a series of late-notice notifications until amounts are either collected, contractually written off in accordance with contracted rates or determined to be uncollectible, typically after 90 to 240 days. Receivables determined to be uncollectible are written off and such amounts are applied to our estimate of allowance for bad debts as previously established in accordance with our policy for bad debt expense. The amount of actual write-offs of account balances for each of our subsidiaries is continuously compared to established allowances for bad debt to ensure that such allowances are adequate. At June 30, 2017, our physician services segment's net accounts receivable represented 70 days of revenue outstanding, which is an increase from 63 days outstanding at December 31, 2016 (which excluded the results from EHH). The increase in days is due to including the impact of EHH's physician services business, which historically has a longer billing and collection cycle, as it is primarily focused on emergency department services. The increase is due in part to recent acquisitions completed during the six months ended June 30, 2017 and year ended December 31, 2016, as it is not unusual for us to experience delays in our ability to bill for procedures until certain administrative procedures are finalized. In addition, we are currently migrating the billing of certain contracts to new billing systems, which we expect will improve efficiency in the billing cycle during 2017. As a result of this process, we are experiencing expected delays in our collections for our physician services. At both June 30, 2017 and December 31, 2016, our ambulatory services segment net accounts receivable represented 33 days of revenue outstanding.
As of June 30, 2017, we had insurance collateral of $100.5 million, which is comprised of restricted cash and available-for-sale securities that are restricted for the purpose of satisfying the obligations of our wholly owned captive insurance companies.
Investing activities. Net cash used in investing activities was $590.5 million for the six months ended June 30, 2017 compared to $325.2 million for the six months ended June 30, 2016. The change was primarily related to the funding of acquisitions and capital expenditures that occurred during the six months ended June 30, 2017.
During the six months ended June 30, 2017, we had total acquisition and capital expenditures of $576.4 million, which primarily included:
Financing activities. Net cash provided by financing activities was $344.8 million for the six months ended June 30, 2017 compared to $97.6 million for the six months ended June 30, 2016. For the six months ended June 30, 2017, we had net proceeds on long-term borrowings of $484.0 million, which included gross proceeds of $798.3 million and payments of $314.3 million. Our proceeds primarily resulted from $500.0 million of incremental borrowings under our Term Loan B 2023 and from borrowings from the ABL Facility. We used the incremental borrowings from the Term Loan B 2023 to fund acquisitions, to repay amounts outstanding under the ABL Facility, and to pay fees and expenses related to the financing.
During the six months ended June 30, 2017, we repurchased approximately 130,160 shares of our common stock by withholding a portion of employee restricted stock that vested, with a value of approximately $8.9 million, to cover payroll withholding taxes in accordance with the restricted stock agreements.
Our Company Preferred Stock paid dividends at an annual rate of 5.25% of the initial liquidation preference of $100 per share. Dividends accrued and cumulated from the date of issuance and, to the extent lawful and declared by our Board, was paid on each January 1, April 1, July 1 and October 1 in cash or, at our election (subject to certain limitations), by delivery of any combination of cash and shares of common stock. During the six months ended June 30, 2017, and prior to the mandatory conversion date, July 1, 2017, holders elected to convert 518,879 of our Company Preferred Stock to 941,294 shares of common stock. On July 3, 2017, the first business day following the mandatory conversion date, the remaining 1,206,121 shares outstanding of Company Preferred Stock automatically converted to 2,188,024 shares of common stock. During the six months ended June 30, 2017, our Board declared two dividends, each totaling $1.3125 per share in cash, or $2.3 million, to the holders of Company Preferred Stock. The dividend declared in June 2017 was funded to the paying agent at June 30, 2017 and was paid on July 1, 2017 to stockholders of record as of June 15, 2017. Following mandatory conversion Date, no shares of our Company Preferred Stock were outstanding and all rights of the holders of our Preferred Stock, including dividend rights, terminated.
Pursuant to the Merger, we issued 62,582,161 shares of common stock to the former stockholders of EHH, which represented the conversion of all outstanding common stock of EHH as of December 1, 2016 pursuant to the terms of the of the Merger.