Notes Payable - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Interest incurred and expensed
Interest expense on debt and capital lease obligations	$ 11,897	$ 11,966	$ 34,724	$ 37,560
Noncash interest on derivatives and capital lease obligations, net	4,534	(1,374)	4,883	7,810
Amortization of deferred financing fees	577	544	1,734	1,648
Total interest incurred and expensed on debt and capital lease obligations	$ 17,008	$ 11,136	$ 41,341	$ 47,018