Loans (Balances Of Commercial Loan Portfolio Classes, Disaggregated By PD Grade) (Details)		Sep. 30, 2015 USD ($) number	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($) number	Jun. 30, 2014 USD ($)	Dec. 31, 2013 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses		$ 210,814,000	$ 221,351,000	$ 232,448,000	$ 238,641,000	$ 243,628,000	$ 253,809,000
Total loans collectively evaluated for impairment		16,372,366,000			15,409,050,000
Total loans individually evaluated for impairment		325,470,000			362,844,000
Allowance - collectively evaluated for impairment		151,370,000			169,583,000
Allowance - individually evaluated for impairment		56,525,000			66,219,000
Allowance - purchased credit impaired loans		2,919,000			2,839,000
Purchase credit impaired loans - recorded investment		27,656,000			40,123,000
General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans collectively evaluated for impairment		7,884,924,000			7,141,868,000
Total loans individually evaluated for impairment		26,904,000			33,987,000
Total commercial loans		7,916,838,000			7,180,931,000
Purchase credit impaired loans - recorded investment		5,010,000			5,076,000
Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans collectively evaluated for impairment		1,375,320,000			957,641,000
Total loans individually evaluated for impairment		0			0
Total commercial loans		1,375,320,000			957,641,000
Purchase credit impaired loans - recorded investment		0			0
TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans collectively evaluated for impairment	[1]	305,382,000			325,882,000
Total loans individually evaluated for impairment	[1]	12,755,000			12,875,000
Total commercial loans	[1]	318,137,000			338,757,000
LOCOM valuation allowance		$ 26,200,000			$ 26,200,000
Highest internal grade | number		13			13
Purchase credit impaired loans - recorded investment		$ 0			$ 0
Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans collectively evaluated for impairment		1,437,000,000			1,185,603,000
Total loans individually evaluated for impairment		8,892,000			15,554,000
Total commercial loans		1,464,425,000			1,233,745,000
Purchase credit impaired loans - recorded investment		18,533,000			32,588,000
Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans collectively evaluated for impairment		20,568,000			36,033,000
Total loans individually evaluated for impairment		1,417,000			6,811,000
Total commercial loans		23,619,000			44,649,000
Purchase credit impaired loans - recorded investment		$ 1,634,000			$ 1,805,000
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percent of total commercial loans		100.00%			100.00%
Allowance for loan losses		$ 96,811,000			$ 85,320,000
Total loans collectively evaluated for impairment		11,023,194,000			9,647,027,000
Total loans individually evaluated for impairment		49,968,000			69,227,000
Total commercial loans		11,098,339,000			9,755,723,000
Allowance - collectively evaluated for impairment		87,654,000			75,396,000
Allowance - individually evaluated for impairment		6,743,000			7,143,000
Allowance - purchased credit impaired loans		$ 2,414,000			$ 2,781,000
Percent of loan collectively evaluated for impairment		99.00%			99.00%
Percent of loan individually evaluated for impairment		1.00%			1.00%
Purchase credit impaired loans - recorded investment		$ 25,177,000			$ 39,469,000
Percent of loan purchased-credit impaired		0.00%			0.00%
Commercial Loan P D Grade One [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 530,543,000			$ 441,874,000
Percent of total commercial loans		5.00%			5.00%
Allowance for loan losses		$ 127,000			$ 0
Commercial Loan P D Grade One [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		529,836,000			441,590,000
Commercial Loan P D Grade One [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		0			0
Commercial Loan P D Grade One [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade One [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		707,000			221,000
Commercial Loan P D Grade One [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		0			63,000
Commercial Loan P D Grade Two [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 601,575,000			$ 358,903,000
Percent of total commercial loans		5.00%			4.00%
Allowance for loan losses		$ 322,000			$ 338,000
Commercial Loan P D Grade Two [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		590,614,000			355,805,000
Commercial Loan P D Grade Two [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		0			0
Commercial Loan P D Grade Two [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Two [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		10,835,000			2,854,000
Commercial Loan P D Grade Two [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		126,000			244,000
Commercial Loan P D Grade Three [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 872,195,000			$ 487,791,000
Percent of total commercial loans		8.00%			5.00%
Allowance for loan losses		$ 311,000			$ 264,000
Commercial Loan P D Grade Three [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		453,831,000			412,110,000
Commercial Loan P D Grade Three [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		327,776,000			46,838,000
Commercial Loan P D Grade Three [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Three [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		90,588,000			28,750,000
Commercial Loan P D Grade Three [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		0			93,000
Commercial Loan P D Grade Four [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 1,248,043,000			$ 624,055,000
Percent of total commercial loans		11.00%			6.00%
Allowance for loan losses		$ 949,000			$ 671,000
Commercial Loan P D Grade Four [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		822,515,000			446,092,000
Commercial Loan P D Grade Four [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		315,061,000			148,852,000
Commercial Loan P D Grade Four [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Four [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		110,165,000			28,815,000
Commercial Loan P D Grade Four [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		302,000			296,000
Commercial Loan P D Grade Five [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 1,671,220,000			$ 1,368,359,000
Percent of total commercial loans		15.00%			14.00%
Allowance for loan losses		$ 6,901,000			$ 2,741,000
Commercial Loan P D Grade Five [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		1,190,085,000			947,041,000
Commercial Loan P D Grade Five [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		239,391,000			177,435,000
Commercial Loan P D Grade Five [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Five [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		234,729,000			239,166,000
Commercial Loan P D Grade Five [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		7,015,000			4,717,000
Commercial Loan P D Grade Six [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 1,902,487,000			$ 1,557,150,000
Percent of total commercial loans		17.00%			16.00%
Allowance for loan losses		$ 10,630,000			$ 1,790,000
Commercial Loan P D Grade Six [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		1,201,553,000			1,090,900,000
Commercial Loan P D Grade Six [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		350,401,000			275,710,000
Commercial Loan P D Grade Six [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Six [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		347,740,000			184,961,000
Commercial Loan P D Grade Six [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		2,793,000			5,579,000
Commercial Loan P D Grade Seven [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 1,735,832,000			$ 1,640,673,000
Percent of total commercial loans		16.00%			17.00%
Allowance for loan losses		$ 13,891,000			$ 2,777,000
Commercial Loan P D Grade Seven [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		1,278,443,000			1,178,283,000
Commercial Loan P D Grade Seven [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		98,262,000			193,667,000
Commercial Loan P D Grade Seven [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Seven [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		354,457,000			262,318,000
Commercial Loan P D Grade Seven [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		4,670,000			6,405,000
Commercial Loan P D Grade Eight [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 916,885,000			$ 1,022,759,000
Percent of total commercial loans		8.00%			10.00%
Allowance for loan losses		$ 13,953,000			$ 2,339,000
Commercial Loan P D Grade Eight [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		747,760,000			747,305,000
Commercial Loan P D Grade Eight [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		18,189,000			88,114,000
Commercial Loan P D Grade Eight [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Eight [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		150,375,000			183,145,000
Commercial Loan P D Grade Eight [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		561,000			4,195,000
Commercial Loan P D Grade Nine [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 449,445,000			$ 668,978,000
Percent of total commercial loans		4.00%			7.00%
Allowance for loan losses		$ 8,310,000			$ 4,559,000
Commercial Loan P D Grade Nine [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		377,998,000			540,472,000
Commercial Loan P D Grade Nine [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		26,240,000			18,251,000
Commercial Loan P D Grade Nine [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Nine [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		42,995,000			107,636,000
Commercial Loan P D Grade Nine [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		2,212,000			2,619,000
Commercial Loan P D Grade Ten [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 219,315,000			$ 341,280,000
Percent of total commercial loans		2.00%			3.00%
Allowance for loan losses		$ 4,635,000			$ 4,001,000
Commercial Loan P D Grade Ten [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		188,711,000			291,984,000
Commercial Loan P D Grade Ten [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		0			8,774,000
Commercial Loan P D Grade Ten [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Ten [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		30,515,000			39,306,000
Commercial Loan P D Grade Ten [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		89,000			1,216,000
Commercial Loan P D Grade Eleven [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 215,725,000			$ 350,966,000
Percent of total commercial loans		2.00%			4.00%
Allowance for loan losses		$ 5,861,000			$ 7,538,000
Commercial Loan P D Grade Eleven [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		186,974,000			314,927,000
Commercial Loan P D Grade Eleven [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		0			0
Commercial Loan P D Grade Eleven [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Eleven [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		28,004,000			33,214,000
Commercial Loan P D Grade Eleven [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		747,000			2,825,000
Commercial Loan P D Grade Twelve [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 90,447,000			$ 136,728,000
Percent of total commercial loans		1.00%			1.00%
Allowance for loan losses		$ 2,975,000			$ 1,383,000
Commercial Loan P D Grade Twelve [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		80,836,000			106,550,000
Commercial Loan P D Grade Twelve [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		0			0
Commercial Loan P D Grade Twelve [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Twelve [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		9,095,000			29,250,000
Commercial Loan P D Grade Twelve [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		516,000			928,000
Commercial Loan P D Grade Thirteen [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 421,665,000			$ 451,103,000
Percent of total commercial loans		4.00%			5.00%
Allowance for loan losses		$ 4,256,000			$ 6,716,000
Commercial Loan P D Grade Thirteen [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		112,423,000			115,198,000
Commercial Loan P D Grade Thirteen [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		0			0
Commercial Loan P D Grade Thirteen [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	305,382,000			325,882,000
Commercial Loan P D Grade Thirteen [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		3,600,000			8,085,000
Commercial Loan P D Grade Thirteen [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		260,000			1,938,000
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 147,817,000			$ 196,408,000
Percent of total commercial loans		1.00%			2.00%
Allowance for loan losses		$ 14,533,000			$ 40,279,000
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member] | General C I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		123,345,000			153,611,000
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member] | Loans To Mortgage Companies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		0			0
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member] | TRUPs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade	[1]	0			0
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member] | Income C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		23,195,000			37,882,000
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member] | Residential C R E [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loan, Disaggregated by PD grade		$ 1,277,000			$ 4,915,000

[1] Balances as of September 30 , 2015 and 2014 , each presented net of $ 26.2 million in lower of cost or market (“LOCOM”) valuation allowance. Based on the underlying structure of the notes, the highest possible internal grade is " 13 ".