Segment Information (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Subcategory revenues
Sales	$ 183,998	$ 184,227	$ 318,733	$ 349,749
Core Products [Member]
Subcategory revenues
Sales	154,980	132,099	259,691	237,680
Core Products [Member] | Broadband Access (included in Carrier Systems) [Member]
Subcategory revenues
Sales	106,042	77,062	155,524	128,844
Core Products [Member] | Optical Access (included in Carrier Systems) [Member]
Subcategory revenues
Sales	14,003	22,008	28,258	42,924
Core Products [Member] | Internetworking (NetVanta & Multi-service Access Gateways) (included in Business Networking) [Member]
Subcategory revenues
Sales	34,935	33,029	75,909	65,912
Legacy Products [Member]
Subcategory revenues
Sales	29,018	52,128	59,042	112,069
Legacy Products [Member] | HDSL (does not include T1) (included in Loop Access) [Member]
Subcategory revenues
Sales	19,465	34,049	38,424	74,994
Legacy Products [Member] | Other products (excluding HDSL) [Member]
Subcategory revenues
Sales	$ 9,553	$ 18,079	$ 20,618	$ 37,075