Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jan. 01, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating lease, right-of-use assets	$ 24,444,000
Operating lease liability	33,258,000
Accounting Standards Update 2016-02
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating lease, right-of-use assets		$ 27,000,000.0
Operating lease liability		$ 36,200,000
Accounting Standards Update 2018-15
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Implementation costs related to hosting arrangements	$ 0