Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Jan. 01, 2019
Accounting Standards Update 2016-02
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Office lease liabilities		$ 4.8
Office lease right-of-use assets		$ 4.8
Pro Forma | Accounting Standards Update 2018-11
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating lease, expense	$ 1.6