Condensed Financial Information Of Parent Company Parent Company Information (Details 1) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Investment Income, Dividend									$ 1,739	$ 1,866	$ 2,575
Total Income									1,310,305
Interest Expense	$ 40,974	$ 32,325	$ 26,182	$ 21,275	$ 21,641	$ 19,276	$ 17,071	$ 14,957	120,756	72,945	54,621
Income Tax Expense (Benefit)	(39,015)	(41,289)	42,286	45,388	$ (56,440)	$ (37,945)	$ (54,902)	$ (47,626)	(167,978)	(196,913)	(205,770)
Net earnings	$ 115,041	$ 116,287	$ 115,735	$ 118,276					465,339	357,818	352,166
Parent Only
Condensed Financial Statements, Captions [Line Items]
Other Income									8,358	3,393	2,146
Investment Income, Dividend									684,000	265,000	259,000
Total Income									692,358	268,393	261,146
Interest Expense									6,550	5,519	4,816
Operating Expenses									10,068	8,273	7,732
Total Expenses									16,618	13,792	12,548
Net earnings from continuing operations									675,740	254,601	248,598
Income Tax Expense (Benefit)									7,262	19,957	2,612
Income Loss From Continuing Operations Before Income Loss From Equity Method Investments									683,002	274,558	251,210
Income (Loss) from Equity Method Investments, Net of Dividends or Distributions									(217,663)	83,260	100,956
Net earnings									$ 465,339	$ 357,818	$ 352,166