Equity - Schedule of Stockholders Equity (Parenthetical) (Details) - shares shares in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Stockholders Equity Note [Abstract]
Shares Purchased for Tax Withholding for Share Based Compensation	104,000	131,000

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