Mergers and Acquisitions	3 Months Ended
Dec. 31, 2017
Business Combinations [Abstract]
Mergers and Acquisitions	Mergers and Acquisitions On October 2, 2017, we completed the acquisition of Glumac, headquartered in Portland, Oregon. Glumac is a leader in sustainable infrastructure design with more than 300 employees and is part of our GSG segment. The fair value of the purchase price for Glumac was $38.4 million. This amount is comprised of $19.0 million of cash payments made to the sellers, $1.0 million held in escrow and included in current liabilities for pending resolution of the closing balance sheet, and $18.4 million of estimated fair value of contingent earn-out obligations, with a maximum of $20.0 million payable, based upon the achievement of specified operating income targets in each of the three years following the acquisition. In the second quarter of fiscal 2017, we acquired Eco Logical Australia (“ELA”), headquartered in Sydney, Australia. ELA is a multi-disciplinary consulting firm with over 160 staff that provides innovative, high-end environmental and ecological services, and is part of our CIG segment. The fair value of the purchase price for ELA was $9.9 million. This amount consists of $8.3 million of cash payments made to the sellers and $1.6 million of estimated fair value of contingent earn-out obligations, with a maximum of $1.7 million payable, based upon the achievement of specified operating income targets in each of the two years following the acquisition. Goodwill additions resulting from the above business combinations are primarily attributable to the existing workforce of the acquired companies and the synergies expected to arise after the acquisitions. The goodwill addition related to the fiscal 2018 acquisition primarily represents the value of a workforce with distinct expertise in the sustainable infrastructure design market. The goodwill addition related to the fiscal 2017 acquisition primarily represents the value of a workforce with distinct expertise in the environmental and ecological markets. In addition, these acquired capabilities, when combined with our existing global consulting and engineering business, result in opportunities that allow us to provide services under contracts that could not have been pursued individually by either us or the acquired companies. The results of these acquisitions were included in our consolidated financial statements from their respective closing dates. These acquisitions were not considered material to our consolidated financial statements. As a result, no pro forma information has been provided. Backlog, client relations and trade names intangible assets include the fair value of existing contracts and the underlying customer relationships with lives ranging from 1 to 10 years, and trade names with lives ranging from 3 to 5 years. For detailed information regarding our intangible assets, see Note 4, "Goodwill and Intangible Assets". Most of our acquisition agreements include contingent earn-out agreements, which are generally based on the achievement of future operating income thresholds. The contingent earn-out arrangements are based on our valuations of the acquired companies, and reduce the risk of overpaying for acquisitions if the projected financial results are not achieved. The fair values of any earn-out arrangements are included as part of the purchase price of the acquired companies on their respective acquisition dates. For each transaction, we estimate the fair value of contingent earn-out payments as part of the initial purchase price and record the estimated fair value of contingent consideration as a liability in “Current contingent earn-out liabilities” and “Long-term contingent earn-out liabilities” on our consolidated balance sheets. We consider several factors when determining that contingent earn-out liabilities are part of the purchase price, including the following: (1) the valuation of our acquisitions is not supported solely by the initial consideration paid, and the contingent earn-out formula is a critical and material component of the valuation approach to determining the purchase price; and (2) the former owners of acquired companies that remain as key employees receive compensation other than contingent earn-out payments at a reasonable level compared with the compensation of our other key employees. The contingent earn-out payments are not affected by employment termination. We measure our contingent earn-out liabilities at fair value on a recurring basis using significant unobservable inputs classified within Level 3 of the fair value hierarchy. We use a probability-weighted discounted income approach as a valuation technique to convert future estimated cash flows to a single present value amount. The significant unobservable inputs used in the fair value measurements are operating income projections over the earn-out period (generally two or three years), and the probability outcome percentages we assign to each scenario. Significant increases or decreases to either of these inputs in isolation would result in a significantly higher or lower liability, with a higher liability capped by the contractual maximum of the contingent earn-out obligation. Ultimately, the liability will be equivalent to the amount paid, and the difference between the fair value estimate and amount paid will be recorded in earnings. The amount paid that is less than or equal to the contingent earn-out liability on the acquisition date is reflected as cash used in financing activities in our consolidated statements of cash flows. Any amount paid in excess of the contingent earn-out liability on the acquisition date is reflected as cash used in operating activities. We review and re-assess the estimated fair value of contingent consideration on a quarterly basis, and the updated fair value could differ materially from the initial estimates. Changes in the estimated fair value of our contingent earn-out liabilities related to the time component of the present value calculation are reported in interest expense. Adjustments to the estimated fair value related to changes in all other unobservable inputs are reported in operating income. We had no adjustments to our contingent earn-out liabilities in the first quarters of fiscal 2018 and 2017. At December 31, 2017, there was a total potential maximum of $28.9 million of outstanding contingent consideration related to acquisitions. Of this amount, $21.1 million was estimated as the fair value and accrued on our consolidated balance sheet. Subsequent Event. On January 17, 2018, we announced a definitive agreement to acquire Norman Disney & Young (“NDY”), a leader in sustainable infrastructure engineering design. NDY is an Australian-based global engineering design firm with more than 700 professionals operating in offices throughout Australia, the Asia-Pacific region, the United Kingdom, and Canada. The acquisition is subject to the satisfaction of customary closing conditions and is expected to be completed during the second quarter of fiscal 2018.

Mergers and Acquisitions

On October 2, 2017, we completed the acquisition of Glumac, headquartered in Portland, Oregon. Glumac is a leader in sustainable infrastructure design with more than 300 employees and is part of our GSG segment. The fair value of the purchase price for Glumac was $38.4 million. This amount is comprised of $19.0 million of cash payments made to the sellers, $1.0 million held in escrow and included in current liabilities for pending resolution of the closing balance sheet, and $18.4 million of estimated fair value of contingent earn-out obligations, with a maximum of $20.0 million payable, based upon the achievement of specified operating income targets in each of the three years following the acquisition.

In the second quarter of fiscal 2017, we acquired Eco Logical Australia (“ELA”), headquartered in Sydney, Australia. ELA is a multi-disciplinary consulting firm with over 160 staff that provides innovative, high-end environmental and ecological services, and is part of our CIG segment. The fair value of the purchase price for ELA was $9.9 million. This amount consists of $8.3 million of cash payments made to the sellers and $1.6 million of estimated fair value of contingent earn-out obligations, with a maximum of $1.7 million payable, based upon the achievement of specified operating income targets in each of the two years following the acquisition.

Goodwill additions resulting from the above business combinations are primarily attributable to the existing workforce of the acquired companies and the synergies expected to arise after the acquisitions. The goodwill addition related to the fiscal 2018 acquisition primarily represents the value of a workforce with distinct expertise in the sustainable infrastructure design market. The goodwill addition related to the fiscal 2017 acquisition primarily represents the value of a workforce with distinct expertise in the environmental and ecological markets. In addition, these acquired capabilities, when combined with our existing global consulting and engineering business, result in opportunities that allow us to provide services under contracts that could not have been pursued individually by either us or the acquired companies. The results of these acquisitions were included in our consolidated financial statements from their respective closing dates. These acquisitions were not considered material to our consolidated financial statements. As a result, no pro forma information has been provided.

Backlog, client relations and trade names intangible assets include the fair value of existing contracts and the underlying customer relationships with lives ranging from 1 to 10 years, and trade names with lives ranging from 3 to 5 years. For detailed information regarding our intangible assets, see Note 4, "Goodwill and Intangible Assets".

Most of our acquisition agreements include contingent earn-out agreements, which are generally based on the achievement of future operating income thresholds. The contingent earn-out arrangements are based on our valuations of the acquired companies, and reduce the risk of overpaying for acquisitions if the projected financial results are not achieved. The fair values of any earn-out arrangements are included as part of the purchase price of the acquired companies on their respective acquisition dates. For each transaction, we estimate the fair value of contingent earn-out payments as part of the initial purchase price and record the estimated fair value of contingent consideration as a liability in “Current contingent earn-out liabilities” and “Long-term contingent earn-out liabilities” on our consolidated balance sheets. We consider several factors when determining that contingent earn-out liabilities are part of the purchase price, including the following: (1) the valuation of our acquisitions is not supported solely by the initial consideration paid, and the contingent earn-out formula is a critical and material component of the valuation approach to determining the purchase price; and (2) the former owners of acquired companies that remain as key employees receive compensation other than contingent earn-out payments at a reasonable level compared with the compensation of our other key employees. The contingent earn-out payments are not affected by employment termination.

We measure our contingent earn-out liabilities at fair value on a recurring basis using significant unobservable inputs classified within Level 3 of the fair value hierarchy. We use a probability-weighted discounted income approach as a valuation technique to convert future estimated cash flows to a single present value amount. The significant unobservable inputs used in the fair value measurements are operating income projections over the earn-out period (generally two or three years), and the probability outcome percentages we assign to each scenario. Significant increases or decreases to either of these inputs in isolation would result in a significantly higher or lower liability, with a higher liability capped by the contractual maximum of the contingent earn-out obligation. Ultimately, the liability will be equivalent to the amount paid, and the difference between the fair value estimate and amount paid will be recorded in earnings. The amount paid that is less than or equal to the contingent earn-out liability on the acquisition date is reflected as cash used in financing activities in our consolidated statements of cash flows. Any amount paid in excess of the contingent earn-out liability on the acquisition date is reflected as cash used in operating activities.

We review and re-assess the estimated fair value of contingent consideration on a quarterly basis, and the updated fair value could differ materially from the initial estimates. Changes in the estimated fair value of our contingent earn-out liabilities related to the time component of the present value calculation are reported in interest expense. Adjustments to the estimated fair value related to changes in all other unobservable inputs are reported in operating income. We had no adjustments to our contingent earn-out liabilities in the first quarters of fiscal 2018 and 2017.

At December 31, 2017, there was a total potential maximum of $28.9 million of outstanding contingent consideration related to acquisitions. Of this amount, $21.1 million was estimated as the fair value and accrued on our consolidated balance sheet.

Subsequent Event. On January 17, 2018, we announced a definitive agreement to acquire Norman Disney & Young (“NDY”), a leader in sustainable infrastructure engineering design. NDY is an Australian-based global engineering design firm with more than 700 professionals operating in offices throughout Australia, the Asia-Pacific region, the United Kingdom, and Canada. The acquisition is subject to the satisfaction of customary closing conditions and is expected to be completed during the second quarter of fiscal 2018.