Stockholders' Equity (Details Textuals) - 401(k) Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Contribution Benefit Plans Disclosures [Line Items]
Employer contribution rate	100.00%
Employer's matching contributions	$ 6.3	$ 6.2	$ 7.1
Maximum
Defined Contribution Benefit Plans Disclosures [Line Items]
Employee contribution rate	6.00%