Stock-Based Compensation (Stock-based Compensation Arrangements) (Details) In Thousands, unless otherwise specified	Mar. 31, 2015
2011 EIP Plan, 2002 EIP Plan and 2002 Non-Employee Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance	33,950
Remaining shares available for grant	5,978
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance	2,000
Remaining shares available for grant	573