Condensed Financial Information Of Parent Company Parent Company Information (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Net earnings	$ 70,999	$ 62,271	$ 10,555	$ 25,080	$ 3,109	$ 24,163	$ 4,349	$ 13,494	$ 168,905	$ 45,115	$ 56,801
Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract]
Decrease (increase) in other assets									22,708	(9,403)	18,754
Tax effect included in stockholders' equity of restricted stock vesting									(4,625)	(2,133)	(283)
Earned stock compensation									36,474	21,246	5,999
Net Cash Provided by (Used in) Operating Activities, Continuing Operations									332,110	50,252	117,980
Net Cash Provided by (Used in) Investing Activities [Abstract]
Cash acquired in acquisitions, net of cash consideration paid									346,047	273,013	(87,098)
Payments to Acquire Available-for-sale Securities									(236,739)	(550,211)	(485,860)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Tax effect included in stockholders' equity of restricted vesting stock									4,625	2,133	283
Restricted stock surrendered									(22,307)	(13,537)	(1,475)
Cash dividends paid, net									(114,162)	(41,006)	(28,787)
Net Cash Provided by (Used in) Financing Activities, Continuing Operations									(722,864)	(480,173)	(420,114)
Net Cash Provided by (Used in) Continuing Operations									165,804	(16,982)	(131,213)
Cash and Cash Equivalents, at Carrying Value	313,226				147,422				313,226	147,422	164,404	295,617
Supplemental Cash Flow Information [Abstract]
Common stock ($0.01 par value, 200,000,000 and 75,000,000 shares authorized at December 31, 2014 and 2013; 104,219,197 and 46,526,124 shares issued, respectively, includes 1,108,505 and 1,216,524 shares of unvested restricted stock, respectively)	1,042				465				1,042	465
Parent Only
Condensed Financial Statements, Captions [Line Items]
Net earnings									168,905	45,115	56,801
Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract]
Acquisition Related Securities Gain									0	(5,222)	0
Decrease (increase) in other assets									39,874	(609)	711
Increase (Decrease) in Operating Liabilities									310	4,932	(4,122)
Tax effect included in stockholders' equity of restricted stock vesting									4,625	(364)	(102)
Earned stock compensation									41,099	441	715
Income (Loss) from Equity Method Investments, Net of Dividends or Distributions									(38,935)	2,392	(11,213)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations									215,878	46,685	42,790
Net Cash Provided by (Used in) Investing Activities [Abstract]
Cash acquired in acquisitions, net of cash consideration paid									226,960	857	0
Payments to Acquire Available-for-sale Securities									0	0	(1,500)
Net Cash Provided by (Used in) Investing Activities, Continuing Operations									226,960	857	(1,500)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Repayments of Subordinated Debt									0	0	(18,558)
Tax effect included in stockholders' equity of restricted vesting stock									(4,625)	364	102
Restricted stock surrendered										(13,537)	(1,475)
Cash dividends paid, net									(114,162)	(41,006)	(28,787)
Net Cash Provided by (Used in) Financing Activities, Continuing Operations									(141,094)	(54,179)	(48,718)
Net Cash Provided by (Used in) Continuing Operations									301,744	(6,637)	(7,428)
Cash and Cash Equivalents, at Carrying Value	323,579				21,835				323,579	21,835	28,472	35,900
Supplemental Cash Flow Information [Abstract]
Common stock ($0.01 par value, 200,000,000 and 75,000,000 shares authorized at December 31, 2014 and 2013; 104,219,197 and 46,526,124 shares issued, respectively, includes 1,108,505 and 1,216,524 shares of unvested restricted stock, respectively)					$ 242,268					$ 242,268	$ 0