Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 25, 2015
Cash flows from operating activities:
Net (loss) income	$ (164,115)	$ 79,116
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:
Depreciation and amortization	47,835	55,580
Stock-based employee compensation	28,952	25,005
Loss (gain) on disposal of property, plant and equipment	62	(3,647)
Allowance for uncollectible accounts	3,706	1,646
Deferred income taxes	(145,523)	(37,872)
Undistributed earnings and gains from unconsolidated affiliates	(44,647)	(36,908)
Distributions of income from unconsolidated affiliates	41,214	39,948
Contributions to defined benefit pension plans	(30,482)	(29,459)
Gain on pension curtailment	(4,568)
Excess tax benefits from stock-based compensation, operating	(3,093)	(3,931)
Change in assets and liabilities:
Receivables and unbilled revenue	119,362	45,431
Prepaid expenses and other	(2,515)	11,469
Accounts payable and accrued subcontractor costs	(84,328)	(50,511)
Billings in excess of revenue	65,000	(56,630)
Accrued payroll and employee related liabilities	(54,572)	71,753
Other accrued liabilities	36,271	(75,747)
Income tax receivable	18,202	58,540
Long-term employee related liabilities and other	37,106	(23,241)
Net cash (used in) provided by operating activities	(129,947)	78,404
Cash flows from investing activities:
Capital expenditures	(87,680)	(21,506)
Acquisition related payments	(17,901)
Investments in unconsolidated affiliates	(16,596)	(23,897)
Distributions of capital from unconsolidated affiliates	10,456	20,855
Proceeds from sale of operating assets	2,703	39,878
Net cash (used in) provided by investing activities	(109,018)	15,330
Cash flows from financing activities:
Borrowings on long-term debt	1,808,743	1,718,769
Payments on long-term debt	(1,690,254)	(1,962,730)
Repurchases and retirements of common stock	(103,911)	(58,483)
Proceeds from the issuance of preferred stock, net of issuance costs	99,800	191,677
Settlement of tax-withholding obligation on stock-based compensation, financing	(3,720)	(4,339)
Net contributions from noncontrolling interests	74,554	56,136
Net cash provided by (used in) financing activities	185,212	(58,970)
Effect of exchange rate changes on cash	(16,994)	(11,303)
(Decrease) increase in cash and cash equivalents	(70,747)	23,461
Cash and cash equivalents, beginning of period	197,021	131,477
Cash and cash equivalents, end of period	126,274	154,938
Supplemental disclosures:
Cash paid for interest	9,781	11,171
Cash paid for income taxes	$ 7,390	$ 16,637