Stockholders' Equity and Partners' Capital - Narrative (Details) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended 32 Months Ended
May 31, 2019
May 31, 2018
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Dec. 31, 2018
Class Of Stock [Line Items]                
Shares withheld for taxes         34,000      
Shares withheld for taxes, value         $ 1,400,000      
Forward sale agreements, shares of common stock 11,500,000              
Forward sale agreements, price per share $ 41.00              
Forward sale agreements, initial price per share $ 39.36              
Gross proceeds from issuance of common stock         $ 162,270,000 $ 0    
Preferred stock, shares outstanding     6,900,000   6,900,000   6,900,000 6,900,000
Dividend rate         6.00%      
Liquidation value (in USD per share)     $ 25.00   $ 25.00   $ 25.00  
Dividend rate, quarterly basis (in USD per share)         0.375      
Dividend rate, annual basis (in USD per share)         $ 1.50      
Less: dividends paid to preferred stockholders     $ 2,588,000 $ 2,588,000 $ 5,176,000 $ 5,176,000    
Common stock, par value per share (in USD per share)     $ 0.05   $ 0.05   $ 0.05 $ 0.05
May 2018                
Class Of Stock [Line Items]                
Stock repurchase program, remaining authorized repurchase amount   $ 250,000,000.0 $ 250,000,000.0   $ 250,000,000.0   $ 250,000,000.0  
Stock repurchase program, period in force   18 months            
Stock repurchase program, repurchase of common shares (in shares)         0      
Forward Sale Agreements                
Class Of Stock [Line Items]                
Issuance of common shares (in shares)         1,900,000      
Gross proceeds from issuance of common stock         $ 76,000,000.0      
ATM Program, November 2016                
Class Of Stock [Line Items]                
Issuance of common shares (in shares)         2,300,000   2,400,000  
Gross proceeds from issuance of common stock         $ 91,400,000      
Common stock, par value per share (in USD per share)     $ 0.05   $ 0.05   $ 0.05  
Common stock authorized         $ 500,000,000.0      
Gross proceeds capacity remaining     $ 404,900,000   $ 404,900,000   $ 404,900,000  
Share issued during the period (in USD per share)         $ 39.19      
ATM Program, Forward Sales                
Class Of Stock [Line Items]                
Issuance of common shares (in shares)         1,800,000