Recent Accounting Pronouncements Revenue Recognition - Effect on Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Prepaid expenses and other current assets	$ 201,626	$ 160,094
Total current assets	1,568,391	1,322,893
Direct financing leases and other assets	606,629	570,706
Total assets	13,051,084	11,463,999	$ 10,912,213
Accrued expenses and other current liabilities	630,493	589,603
Total current liabilities	2,292,321	2,014,975
Other non-current liabilities	849,946	812,642
Deferred income taxes	1,304,844	1,211,129
Total liabilities	10,140,757	8,622,328
Retained earnings	2,710,696	2,471,677
Total shareholders’ equity	2,910,327	2,841,671	$ 2,057,656	$ 1,987,111
Total liabilities and shareholders’ equity	$ 13,051,084	11,463,999
As Previously Reported | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Prepaid expenses and other current assets		159,500
Total current assets		1,322,300
Direct financing leases and other assets		559,500
Total assets		11,452,200
Accrued expenses and other current liabilities		587,400
Total current liabilities		2,012,800
Other non-current liabilities		812,100
Deferred income taxes		1,208,800
Total liabilities		8,617,200
Retained earnings		2,465,000
Total shareholders’ equity		2,835,000
Total liabilities and shareholders’ equity		11,452,200
Adjustment | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Prepaid expenses and other current assets		600
Total current assets		600
Direct financing leases and other assets		11,200
Total assets		11,800
Accrued expenses and other current liabilities		2,200
Total current liabilities		2,200
Other non-current liabilities		500
Deferred income taxes		2,300
Total liabilities		5,100
Retained earnings		6,700
Total shareholders’ equity		6,700
Total liabilities and shareholders’ equity		$ 11,700