Stockholders' Equity - Narrative - Preferred Stock (Details)	12 Months Ended
	Dec. 31, 2017 class shares	Dec. 31, 2018 shares
Equity [Abstract]
Preferred stock, number of classes or series the Board of Directors is authorized to classify or reclassify | class	1
Preferred stock, number of classes or series the Board of Directors is authorized to issue | class	1
Preferred stock, shares issued (in shares) | shares	0	0
Preferred stock, shares outstanding (in shares) | shares	0	0