Employee Benefit Plan	12 Months Ended
Dec. 31, 2018
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plan	13. Employee Benefit Plan We sponsor a 401(k) Plan, which stipulates that eligible employees can elect to contribute to the 401(k) Plan, subject to certain limitations of eligible compensation. We match employee contributions up to a maximum of 3% of employee salary for the years ended December 31, 2018, 2017 and 2016. During the years ended December 31, 2018, 2017 and 2016, we recognized total expense of $1.3 million, $0.9 million and $0.8 million, respectively, relating to these contributions.

The entire disclosure for pension and other postretirement benefits.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-URI http://asc.fasb.org/topic&trid=2235017

Name:	us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration