Segment Information (Details) $ in Thousands	3 Months Ended		12 Months Ended	26 Months Ended
	Dec. 30, 2017 USD ($) Segment	Dec. 31, 2016 USD ($)	Sep. 30, 2017 Segment	Dec. 30, 2017 USD ($)
Number of operating segments | Segment	2		3
Number of reportable segments | Segment	2		3
Revenue	$ 306,644	$ 286,327
Cost of Revenue	82,958	82,115
Gross margin	223,686	204,212
Sales and marketing	99,315	90,690
General and administrative	35,004	36,695
Restructuring charges	105	6,285		$ 85,500
Amortization of acquired intangible assets	7,821	8,067
Operating income	17,472	4,561
Interest expense	(10,047)	(10,315)
Non operating income and expenses	954	749
Income (loss) before income taxes	6,471	(6,503)
Operating Segments
Revenue	306,644	286,327
Cost of Revenue	134,469	127,863
Gross margin	172,175	158,464
Operating Segments | Software Products segment
Revenue	265,190	240,219
Cost of Revenue	99,689	90,039
Gross margin	165,501	150,180
Operating Segments | Professional Services segment
Revenue	41,454	46,108
Cost of Revenue	34,780	37,824
Gross margin	6,674	8,284
Unallocated
Sales and marketing	94,436	87,069
General and administrative	27,432	28,050
Restructuring charges	105	6,285
Amortization of acquired intangible assets	14,496	14,455
Stock-based compensation	18,331	17,988
Other unallocated operating expenses	$ (97)	$ 56