Net Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2015

Earnings Per Share [Abstract]

Anti-Dilutive Securities Excluded from Computation of Earnings Per Share

The following instruments have been excluded from the calculation of diluted net loss per share, as their effect would be anti-dilutive.

	Three Months Ended March 31,
Common shares issuable upon:	2015		2014
	(in thousands)
Conversion of convertible senior notes		1,438		1,438
Exercise or vesting of share-based awards		879		851