Equity Compensation (401(k) Plan) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($) shares
Defined Contribution Plan Disclosure [Line Items]
Maximum amount of employees' gross pay the employee may contribute (as a percent)	4.50%
Shares contributed (in shares) | shares	34,854
Expenses associated with contribution | $	$ 0.6
First 1% of employees' salary
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution (as a percent)	100.00%
Employees' gross pay for which the employer contributes a matching contribution (as a percent)	1.00%
Second 5% of employees' salary
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution (as a percent)	70.00%
Employees' gross pay for which the employer contributes a matching contribution (as a percent)	5.00%