CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 26, 2017	Mar. 27, 2016
Cash flows from operating activities
Net income/(loss)	$ 13,115	$ (13,586)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	16,153	15,472
Stock-based compensation expense	3,958	2,931
Undistributed (income)/loss of joint ventures	(173)	41,896
Long-term retirement benefit obligations	(6,458)	(6,886)
Uncertain tax positions	80	460
Other-net	1,708	2,882
Changes in operating assets and liabilities:
Accounts receivable-net	20,442	37,162
Other current assets	442	(1,808)
Accounts payable, accrued payroll and other liabilities	(34,995)	(94,399)
Unexpired subscriptions	15,859	3,867
Net cash provided by/(used in) operating activities	30,131	(12,009)
Cash flows from investing activities
Purchases of marketable securities	(80,108)	(34,912)
Maturities of marketable securities	117,465	143,965
Cash distribution from corporate-owned life insurance	0	38,000
Business acquisitions	0	(12,250)
Change in restricted cash	(15)	(470)
Capital expenditures	(8,032)	(10,542)
Other-net	510	(1,026)
Net cash provided by investing activities	29,820	122,765
Cash flows from financing activities
Repayment of debt and capital lease obligations	(138)	(138)
Dividends paid	(6,473)	(6,461)
Stock issuances	445	0
Repurchases	0	(15,684)
Share-based compensation tax withholding	(3,726)	(8,675)
Net cash used in financing activities	(9,892)	(30,958)
Net increase in cash and cash equivalents	50,059	79,798
Effect of exchange rate changes on cash	213	119
Cash and cash equivalents at the beginning of the period	100,692	105,776
Cash and cash equivalents at the end of the period	$ 150,964	$ 185,693