Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Measured at fair value on a recurring basis:
Restricted cash	$ 6,019	$ 21,090	$ 40,096
Cross-currency swap asset	2,283	0
Significant Unobservable Inputs (Level 3)
Disclosed at fair value:
Mortgage notes, term loans and construction loan	1,365,812	1,807,199
Measured at fair value on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Measured at fair value on a recurring basis:
Cash and cash equivalents	208,078	48,873
Restricted cash	6,019	21,090
Measured at fair value on a recurring basis | Significant Observable Inputs (Level 2) | Interest rate swap liability
Measured at fair value on a recurring basis:
Interest rate swap liability	0	2,463
Measured at fair value on a recurring basis | Significant Observable Inputs (Level 2) | Cross Currency Swap Agreements
Measured at fair value on a recurring basis:
Cross-currency swap asset	2,283	0
Measured at fair value on a non-recurring basis | Significant Unobservable Inputs (Level 3)
Long-lived assets written down:
Property, plant and equipment	0	2,576
Pension | Measured at fair value on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Measured at fair value on a recurring basis:
Restricted cash	30,281	32,626
Pension | Measured at fair value on a recurring basis | Significant Observable Inputs (Level 2)
Measured at fair value on a recurring basis:
Interest rate swap liability	$ 29,456	$ 33,102