Debt (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

		December 31,
	Interest rate	2017		2016
Notes due September 2017	5.75%	$	—	$	385,109
Notes due March 2018	5.60%	250,000		250,000
Notes due May 2018	4.75%	—		350,000
Notes due March 2019	6.25%	300,000		300,000
Notes due September 2020	3.625%	300,000		—
Notes due October 2021	3.625%	600,000		600,000
Notes due May 2022	4.125%	400,000		—
Notes due April 2023	4.70%	400,000		—
Notes due March 2024	4.625%	500,000		500,000
Notes due January 2037	5.25%	35,841		115,041
Notes due March 2043	6.70%	425,000		425,000
Term loans	Variable	650,000		450,000
Other debt		5,476		5,677
Principal amount		3,866,317		3,380,827
Less: unamortized costs, net		35,982		15,937
Total debt		3,830,335		3,364,890
Less: current portion long-term debt		271,057		614,485
Long-term debt		$	3,559,278	$	2,750,405

Schedule of Maturities of Long-term Debt

Annual maturities of outstanding debt at December 31, 2017 are as follows:

2018	$	270,000
2019	500,000
2020	730,476
2021	600,000
2022	400,000
Thereafter	1,365,841
Total	$	3,866,317