Fair Value Measurement (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration related to acquisitions	$ 16,594		$ 19,570
Payment of contingent consideration	3,100	$ 1,300
Business Combination, Consideration Transferred, Liabilities Incurred	2,700
Accrued Expenses and Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration related to acquisitions	11,900
Other Noncurrent Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration related to acquisitions	$ 4,700