Equity - Reclassifications Out of Accumulated Other Comprehensive Loss (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss)      
Beginning equity balance, value $ 2,294,595 $ 2,385,397 $ 2,485,724
Amounts reclassified from accumulated other comprehensive loss to:      
Interest expense 98,813 93,551 93,001
Total other comprehensive loss (17,407) (60,119) (68,677)
Ending equity balance, value 2,315,004 2,294,595 2,385,397
Accumulated Other Comprehensive Loss      
Accumulated Other Comprehensive Income (Loss)      
Beginning equity balance, value (139,805) (81,007) (13,442)
Other comprehensive loss before reclassifications (16,188) (59,873) (74,751)
Amounts reclassified from accumulated other comprehensive loss to:      
Total (1,219) (246) 6,074
Total other comprehensive loss (17,407) (60,119) (68,677)
Net current-period Other comprehensive income attributable to noncontrolling interests 536 1,321 1,112
Ending equity balance, value (156,676) (139,805) (81,007)
Accumulated Other Comprehensive Loss | Reclassification out of Accumulated Other Comprehensive Income      
Amounts reclassified from accumulated other comprehensive loss to:      
Interest expense 6,339 7,837 7,970
Other income and (expenses) (7,558) (8,083) (1,896)
Gains and Losses on Derivative Instruments      
Accumulated Other Comprehensive Income (Loss)      
Beginning equity balance, value 28,200 7,311 (16,717)
Other comprehensive loss before reclassifications 2,568 21,135 18,365
Amounts reclassified from accumulated other comprehensive loss to:      
Total (1,219) (246) 6,074
Total other comprehensive loss 1,349 20,889 24,439
Net current-period Other comprehensive income attributable to noncontrolling interests 0 0 (411)
Ending equity balance, value 29,549 28,200 7,311
Gains and Losses on Derivative Instruments | Reclassification out of Accumulated Other Comprehensive Income      
Amounts reclassified from accumulated other comprehensive loss to:      
Interest expense 6,339 7,837 7,970
Other income and (expenses) (7,558) (8,083) (1,896)
Gains and Losses on Marketable Securities      
Accumulated Other Comprehensive Income (Loss)      
Beginning equity balance, value (77) (106) (391)
Other comprehensive loss before reclassifications 29 29 285
Amounts reclassified from accumulated other comprehensive loss to:      
Total 0 0 0
Total other comprehensive loss 29 29 285
Net current-period Other comprehensive income attributable to noncontrolling interests 0 0 0
Ending equity balance, value (48) (77) (106)
Gains and Losses on Marketable Securities | Reclassification out of Accumulated Other Comprehensive Income      
Amounts reclassified from accumulated other comprehensive loss to:      
Interest expense 0 0 0
Other income and (expenses) 0 0 0
Foreign Currency Translation Adjustments      
Accumulated Other Comprehensive Income (Loss)      
Beginning equity balance, value (167,928) (88,212) 3,666
Other comprehensive loss before reclassifications (18,785) (81,037) (93,401)
Amounts reclassified from accumulated other comprehensive loss to:      
Total 0 0 0
Total other comprehensive loss (18,785) (81,037) (93,401)
Net current-period Other comprehensive income attributable to noncontrolling interests 536 1,321 1,523
Ending equity balance, value (186,177) (167,928) (88,212)
Foreign Currency Translation Adjustments | Reclassification out of Accumulated Other Comprehensive Income      
Amounts reclassified from accumulated other comprehensive loss to:      
Interest expense 0 0 0
Other income and (expenses) $ 0 $ 0 $ 0