Summary of Significant Accounting Policies (Recently Adopted and Issued Accounting Pronouncements) (Details 2) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Item Effected [Line Items]
Other current assets	$ 105,595	$ 77,128	$ 82,723
Lease Right-of-Use Assets	526,417	369,333	0
Accounts payable and accrued liabilities	507,701	472,549	486,578
Current portion of lease liabilities	92,714	86,747	0
Other Liabilities	27,223	17,401	57,901
Lease Liabilities	$ 477,004	331,520	0
Previous Accounting Guidance [Member]
Item Effected [Line Items]
Other current assets			82,723
Lease Right-of-Use Assets			0
Accounts payable and accrued liabilities			486,578
Current portion of lease liabilities			0
Other Liabilities			57,901
Lease Liabilities			$ 0
Accounting Standards Update 2016-02 [Member]
Item Effected [Line Items]
Other current assets		(5,595)
Lease Right-of-Use Assets		369,333
Accounts payable and accrued liabilities		(14,029)
Current portion of lease liabilities		86,747
Other Liabilities		(40,500)
Lease Liabilities		$ 331,520