Business Acquisitions (Components of Acquisition-Related Costs, Net) (Detail) (USD $)	3 Months Ended	6 Months Ended
Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Business Combinations [Abstract]
Increase (Decrease) in Other Noncurrent Liabilities			$ (7,700,000)
Transition and integration costs	4,590,000	11,636,000	8,429,000	17,899,000
Professional service fees	2,399,000	3,812,000	5,738,000	13,282,000
Business Combination Acquisition Related Adjustments	(187,000)	0	(4,567,000)	0
Total	$ 6,802,000	$ 15,448,000	$ 9,600,000	$ 31,181,000

Acquisition-related costs include those costs related to business and other acquisitions, including potential acquisitions. These costs consist of (i) transition and integration costs, including retention payments, transitional employee costs and earn-out payments treated as compensation expense, as well as the costs of integration-related services provided by third-parties; (ii) professional service fees, including third party costs related to the acquisition, and legal and other professional service fees associated with disputes and regulatory matters related to acquired entities; and (iii) adjustments to acquisition-related items that are required to be marked to fair value each reporting period, such as contingent consideration, and other items related to acquisitions for which the measurement period has ended.

No definition available.

Name:	nuan_AcquisitionRelatedCostsNet
Namespace Prefix:	nuan_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration