Statement of Comprehensive Income Statement of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	$ 85,484	$ 71,273	$ 162,787	$ 123,921
Income Tax Expense (Benefit)	25,965	22,823	49,813	38,125
Net income	59,519	48,450	112,974	85,796
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	22,456	(75,729)	40,500	(87,362)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	7,860	(26,505)	14,175	(30,577)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	14,596	(49,224)	26,325	(56,785)
Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, before Tax	(494)	(568)	(988)	(1,120)
Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, Tax	(173)	(199)	(346)	(392)
Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, Net of Tax	(321)	(369)	(642)	(728)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(80)	2,794	(136)	2,803
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	(28)	978	(48)	982
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	(52)	1,816	(88)	1,821
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax	21,882	(73,503)	39,376	(85,679)
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax	7,659	(25,726)	13,781	(29,987)
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Net of Tax	14,223	(47,777)	25,595	(55,692)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax	0	0	0	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Tax	0	0	0	0
Other Comprehensive Income Defined benefit plan, amortization of gains, before tax	1,631	0	1,631	0
Other comprehensive Income, Defined Benefit Plan, Amortization of Gains, tax	571	0	571	0
Other Comprehensive Income, Defined benefit plan, amortization of gains, after tax	1,060	0	1,060	0
Other Comprehensive Income (Loss), before Tax	24,610	(73,503)	42,104	(85,679)
Other Comprehensive Income (Loss), Tax	8,613	(25,726)	14,735	(29,987)
Other Comprehensive Income (Loss), Net of Tax	15,997	(47,777)	27,369	(55,692)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	110,094	(2,230)	204,891	38,242
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	34,578	(2,903)	64,548	8,138
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	75,516	673	140,343	30,104
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	0	0	0	0
Other Comprehensive Income (Loss), Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service (Cost) Credit, Tax	383	0	383	0
Other Comprehensive Income (Loss), Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service (Cost) Credit, Net of Tax	714	0	714	0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	2,728	0	2,728	0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax	954	0	954	0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	1,774	0	1,774	0
Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax	$ 1,097	$ 0	$ 1,097	$ 0