5. Leases (Tables)

12 Months Ended

Dec. 31, 2016

Leases [Abstract]

Schedule Of Customers Comprising More Than Ten Percent Of Consolidated Revenues [Table Text Block]

For the years ended December 31, 2016, 2015 and 2014, the following customers comprised more than 10.0% of our consolidated revenues:

	Microsoft		Facebook		Fortune 25 Investment Grade-Rated Company
Year ended December 31, 2016	29.7	%	17.6	%	10.3	%
Year ended December 31, 2015	25.2	%	16.9	%	6.5	%
Year ended December 31, 2014	21.6	%	17.4	%	4.7	%

Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]

As of December 31, 2016, future minimum lease payments to be received under noncancellable operating leases are as follows for the years ending December 31 (in thousands):

2017	$	365,642
2018	358,439
2019	292,355
2020	239,842
2021	219,023
2022 and thereafter	751,080
	$	2,226,381