Revenue Recognition - Balance Sheet Impact of Adoption of ASC 606 (Details) - USD ($) $ in Thousands	Dec. 30, 2018	Sep. 30, 2018
ASSETS
Contract assets	$ 126,545	$ 142,882
Deferred tax assets	8,448	8,607
LIABILITIES AND EQUITY
Contract liabilities	155,585	143,270
Income taxes payable	17,349	8,272
Equity:
Retained earnings	977,543	$ 944,965
Recognition Under Previous Guidance
ASSETS
Contract assets	131,885
Deferred tax assets	7,328
LIABILITIES AND EQUITY
Contract liabilities	158,519
Income taxes payable	16,824
Equity:
Retained earnings	978,632
Impact of the Adoption of ASC 606 | Accounting Standards Update 2014-09
ASSETS
Contract assets	(5,340)
Deferred tax assets	1,120
LIABILITIES AND EQUITY
Contract liabilities	(2,934)
Income taxes payable	525
Equity:
Retained earnings	$ (1,089)