Employee Benefit Plan Employee Benefit Plan (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended
Mar. 31, 2010	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Employer matching contribution	50.00%
Maximum contribution of an employee's eligible earnings	6.00%
Defined Benefit Plan, Contributions by Employer		$ 1.9	$ 1.6	$ 1.2

The increase in the fair value of plan assets from contributions made by the employer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration