Revisions of Prior Period Financial Statements Consolidated Statement of Earnings (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of lease and rental									$ 2,153,450	$ 2,036,881	$ 1,925,546
Interest expense									150,434	144,739	140,463
Earnings from continuing operations before income taxes									469,215	338,267	369,015
Provision for income taxes									163,226	118,042	125,740
Earnings from Continuing Operations	$ 75,935	$ 90,811	$ 85,917	$ 53,326	$ 11,483	$ 83,895	$ 75,721	$ 49,126	305,989	220,225	243,275
Net earnings	$ 76,201	$ 90,619	$ 85,159	$ 52,789	$ 11,079	$ 83,617	$ 75,385	$ 48,260	$ 304,768	218,341	237,871
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of lease and rental										(2,400)	(3,400)
Interest expense										2,600	3,300
Earnings from continuing operations before income taxes										(200)	100
Provision for income taxes										(100)	0
Earnings from Continuing Operations										(300)	100
Net earnings										(300)	100
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of lease and rental										2,039,300	1,928,900
Interest expense										142,100	137,200
Earnings from continuing operations before income taxes										338,500	368,900
Provision for income taxes										118,100	125,700
Earnings from Continuing Operations										220,500	243,200
Net earnings										$ 218,600	$ 237,800