Supplemental Cash Flow Information - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stockholders' Equity Note [Line Items]
Cash interest payments	$ (234,102)	$ (384,157)	$ (367,334)
Net income tax cash payments	143,000	130,469	$ 128,709
Series A Preferred Stock
Stockholders' Equity Note [Line Items]
Preferred stock dividends declared and paid	$ (11,103)	$ (18,052)