Supplemental Cash Flow Information (Tables)

9 Months Ended

Sep. 30, 2017

Supplemental Cash Flow Information [Abstract]

Supplemental Disclosure of Cash Flow Information and Non-cash Investing and Financing Activities

	Nine Months Ended September 30,
	2017			2016
Supplemental disclosure of cash flow information:
Interest paid	$	420,317		$	357,094
Income taxes paid	13,853			11,740
Supplemental disclosure of non-cash investing and financing activities:
Increase (decrease) in accounts payable for purchases of property and equipment	(5,282		)	1,390
Purchase of property and equipment under capital leases and installment purchases	25,189			40,295
Preferred stock dividends declared but not paid (see note 9)	29,935			10,997