Intangible Assets and Intangible Liabilities - Summary of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Intangible assets:
Gross amount	$ 592,133	$ 655,194
Accumulated amortization	(156,683)	(143,987)
Intangible assets, Net	435,450	511,207
Intangible liabilities:
Gross amount	217,021	221,672
Accumulated amortization	(62,363)	(41,931)
Intangible Liabilities, Net	$ 154,658	$ 179,741