Long-Term Debt - Debt Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Debt expense recognized	$ 461,897	$ 406,341	$ 394,013
Amortization of deferred financing costs	$ 25,538	$ 24,293	$ 20,103