Employee Benefit Plans (Narrative) (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Benefit Plans Narrative Details
Company contribution match of employee contributions up to 3% of employee pre-tax contributions, percent	100.00%	100.00%	100.00%
Company contribution match of employee contributions of next 3% of employee pre-tax contributions, percent	50.00%	50.00%	50.00%
Matching contributions by company to 401(k) plan	$ 1,600,000	$ 1,100,000	$ 620,000

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