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Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 30, 2017 | Dec. 31, 2016 | Jan. 02, 2016
Revenue Recognition |  |  |
Reimbursable expenses | $ 41,465 | $ 34,482 | $ 33,548
Minimum |  |  |
Revenue Recognition |  |  |
Period in which engagements are generally completed | 3 months |  |
Maximum |  |  |
Revenue Recognition |  |  |
Period in which engagements are generally completed | 6 months |  |

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- Definition Repayment received or receivable for expenses incurred on behalf of a client or customer, other than those reimbursements received by landlords from tenants. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 605 -SubTopic 45 -Section 45 -Paragraph 23 -URI http://asc.fasb.org/extlink&oid=68075638&loc=d3e60722-111653 + Details
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