Subsequent Events	12 Months Ended
Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Business Combination In January 2016, the Company entered into a definitive agreement to acquire BTI Systems Inc., a provider of cloud and metro optical networking systems and software to content, cloud and service providers, for (i) approximately $65.0 million in cash (inclusive of debt) plus cash on hand at closing and (ii) the assumption of 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. The consummation of this acquisition is subject to customary closing conditions. Dividend Declaration On January 27, 2016, the Company announced that it had declared a quarterly cash dividend of $0.10 per share of common stock payable on March 22, 2016 to stockholders of record as of the close of business on March 1, 2016. Stock Repurchase Activities Subsequent to December 31, 2015, through the filing of this Annual Report on Form 10-K, the Company repurchased 3.1 million shares of its common stock, for an aggregate purchase price of $75.0 million at an average price of $23.89 per share, under the 2014 Stock Repurchase Program and were settled prior to the filing of this Report. Under the 2014 Stock Repurchase Program, the Company has $457.5 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 law and other legal requirements. This program may be discontinued at any time.

Subsequent Events

Business Combination

In January 2016, the Company entered into a definitive agreement to acquire BTI Systems Inc., a provider of cloud and metro optical networking systems and software to content, cloud and service providers, for (i) approximately $65.0 million in cash (inclusive of debt) plus cash on hand at closing and (ii) the assumption of 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. The consummation of this acquisition is subject to customary closing conditions.

Dividend Declaration

On January 27, 2016, the Company announced that it had declared a quarterly cash dividend of $0.10 per share of common stock payable on March 22, 2016 to stockholders of record as of the close of business on March 1, 2016.

Stock Repurchase Activities

Subsequent to December 31, 2015, through the filing of this Annual Report on Form 10-K, the Company repurchased 3.1 million shares of its common stock, for an aggregate purchase price of $75.0 million at an average price of $23.89 per share, under the 2014 Stock Repurchase Program and were settled prior to the filing of this Report. Under the 2014 Stock Repurchase Program, the Company has $457.5 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 law and other legal requirements. This program may be discontinued at any time.