Equity and EPS (Details)	12 Months Ended
	Dec. 31, 2018 board_member shares	Dec. 31, 2017 shares	Dec. 31, 2016 shares
Equity [Abstract]
Number of board members that common stockholders are entitled to elect	4
Total number of board members	9
Number of board members preferred stock shareholders entitled to elect	5
Board of directors, term of service	1 year
Minimum single shareholder ownership percentage to call special stockholder meeting (as a percent)	10.00%
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Participating securities (in shares) | shares	326,375	368,492	527,486