XML 84 R60.htm IDEA: XBRL DOCUMENT v3.8.0.1
Fair Value of Derivatives and Financial Instruments Fair Value, by Balance Sheet Grouping (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Preferred Stock, Redemption Date Oct. 01, 2026  
Preferred Stock, Redemption Price Per Share $ 50.00  
Fixed Rate Debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Notes Payable Excluding Interest Rate Swaps and Cap Agreements $ 3,160,000 $ 3,000,000
Notes Payable, Fair Value Disclosure 3,290,000 3,130,000
Floating Rate Debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Notes Payable Excluding Interest Rate Swaps and Cap Agreements 1,300,000 1,500,000
Notes Payable, Fair Value Disclosure 1,300,000 1,500,000
Fair Value, Measurements, Recurring [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Interest Rate Derivative Assets, at Fair Value 3,551 2,364
Interest Rate Derivative Liabilities, at Fair Value 1,316 7,562
Embedded Derivative, Fair Value of Embedded Derivative Asset 21,169 $ 10,783
Embedded Derivative, Gain on Embedded Derivative 10,386  
Business Combinations, Purchase Price Adjustment, Subsequent Adjustment 1,600  
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Change in Unrealized Gain (Loss) $ 8,800