Stockholders' Equity and Partners' Capital (Tables)
 9 Months Ended
Sep. 30, 2017
Equity [Abstract]  
Summary of Dividends Declared
For the nine months ended September 30, 2017, the Corporation's Board of Directors declared the following dividends:
Declaration Date
 
Dividend Per Share
 
Record Date
 
Total Amount
 
Payment Date
 
 
 
 
 
 
(in thousands)
 
 
March 15, 2017
 
$
0.1800

 
March 31, 2017
 
$
87,122

 
April 14, 2017
June 15, 2017
 
$
0.1800

 
June 30, 2017
 
$
82,422

 
July 14, 2017
September 15, 2017
 
$
0.1800

 
September 29, 2017
 
$
82,062

 
October 13, 2017