Subsequent Events	3 Months Ended
Mar. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events BTI Acquisition On April 1, 2016, the Company acquired BTI Systems Inc. (“BTI”), a provider of cloud and metro optical networking systems and software to content, cloud and service providers, for $65.0 million in cash (inclusive of the repayment of $23.9 million of certain outstanding BTI liabilities), subject to adjustments for working capital, cash on hand, and certain tax credits. Additionally, the Company assumed restricted stock units outstanding at closing. The Company believes that this acquisition will allow the Company to accelerate the delivery of open and automated packet optical transport solutions with integrated network management based on BTI Systems' proNX Service Manager and Juniper's Connectivity Services Director, as well as NorthStar Controller. The Company believes that, together, these products provide a unified management interface for multi-layer provisioning of end-to-end services across IP and optical networks. Dividend Declaration On April 28, 2016, the Company announced that it had declared a cash dividend of $0.10 per share of common stock payable on June 22, 2016 to stockholders of record as of the close of business on June 1, 2016. Stock Repurchase Activities Subsequent to March 31, 2016, through the filing of this Report, the Company repurchased 3.8 million shares of its common stock, for an aggregate of $88.0 million at an average purchase price of $23.16 per share, under the 2014 Stock Repurchase Program. Repurchases of 2.8 million shares were settled prior to the filing of this Report and the remaining shares will be settled after the filing date. Under the 2014 Stock Repurchase Program, the Company has $369.6 million authorized funds remaining as of the filing date. Purchases under the Company's stock repurchase program are subject to review of the circumstances in place at the time and will be made from time to time as permitted by securities laws and other legal requirements. This program may be discontinued at any time.

Subsequent Events

BTI Acquisition

On April 1, 2016, the Company acquired BTI Systems Inc. (“BTI”), a provider of cloud and metro optical networking systems and software to content, cloud and service providers, for $65.0 million in cash (inclusive of the repayment of $23.9 million of certain outstanding BTI liabilities), subject to adjustments for working capital, cash on hand, and certain tax credits. Additionally, the Company assumed restricted stock units outstanding at closing. The Company believes that this acquisition will allow the Company to accelerate the delivery of open and automated packet optical transport solutions with integrated network management based on BTI Systems' proNX Service Manager and Juniper's Connectivity Services Director, as well as NorthStar Controller. The Company believes that, together, these products provide a unified management interface for multi-layer provisioning of end-to-end services across IP and optical networks.

Dividend Declaration

On April 28, 2016, the Company announced that it had declared a cash dividend of $0.10 per share of common stock payable on June 22, 2016 to stockholders of record as of the close of business on June 1, 2016.

Stock Repurchase Activities

Subsequent to March 31, 2016, through the filing of this Report, the Company repurchased 3.8 million shares of its common stock, for an aggregate of $88.0 million at an average purchase price of $23.16 per share, under the 2014 Stock Repurchase Program. Repurchases of 2.8 million shares were settled prior to the filing of this Report and the remaining shares will be settled after the filing date. Under the 2014 Stock Repurchase Program, the Company has $369.6 million authorized funds remaining as of the filing date. Purchases under the Company's stock repurchase program are subject to review of the circumstances in place at the time and will be made from time to time as permitted by securities laws and other legal requirements. This program may be discontinued at any time.