Intangible Assets and Intangible Liabilities - Summary of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Intangible assets:
Gross amount	$ 560,809	$ 579,066
Accumulated amortization	(171,221)	(166,841)
Intangible assets, Net	389,588	412,225
Intangible liabilities:
Gross amount	203,674	208,367
Accumulated amortization	(58,536)	(55,349)
Intangible Liabilities, Net	$ 145,138	$ 153,018