Related Party Transactions - Indirect Charges (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 75,094	$ 69,306	$ 66,077
Operating Expense [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	65,347	59,863	57,182
General and Administrative Expense [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 9,747	$ 9,443	$ 8,895