Stock Based Awards and Other Equity Instruments - Summary of Stock Option (Parenthetical) (Details) (Stock Options)	12 Months Ended
Dec. 31, 2014
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options non converted into shares due to net share settlement	628,010

For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer.

No definition available.

Name:	us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration