Goodwill and Intangible Assets (Schedule of Goodwill and Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Goodwill and Intangible Assets [Line Items]
Goodwill, Acquired During Period	$ 0	$ 0	$ 0	$ 228,398
Indefinite-Lived Intangible Assets (Excluding Goodwill)	919	919	919	919
Other intangible assets, net	21,336	27,509	21,336	27,509		25,852
Goodwill and Intangible Assets [Roll Forward]
Total goodwill, beginning of period		343,952	343,952	115,554
Total goodwill, end of period	343,952	343,952	343,952	343,952
CDI current period amortization	(1,456)	(1,666)	(4,516)	(4,388)
Total goodwill and intangible assets, end of period	365,288	371,461	365,288	371,461
Core Deposits [Member]
Goodwill and Intangible Assets [Line Items]
Finite Lived Intangible Assets Acquired During the Period	0	0	0	15,257
Estimated life of CDI, in years			10 years
Goodwill and Intangible Assets [Roll Forward]
Gross core deposit intangible balance, beginning of period					47,698	47,698	47,698	32,441
Accumulated amortization at beginning of period					(25,825)	(22,765)	(19,441)	(16,720)
Core deposit intangible, net, beginning of period	21,873	28,257	24,933	15,721
CDI current period amortization	(1,456)	(1,667)	(4,516)	(4,388)
Total core deposit intangible, end of period	$ 20,417	$ 26,590	$ 20,417	$ 26,590