Fair Value (Fair value measurement recurring) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Assets
Securities available for sale	$ 1,566,592	$ 1,578,434
U.S. government corporations and agencies
Assets
Securities available for sale	5,101	25,766
Mortgage-backed securities
Assets
Securities available for sale	1,220,732	1,242,702
Obligations of states and political subdivisions
Assets
Securities available for sale	326,422	295,982
Corporate debt securities
Assets
Securities available for sale	830	846
Equity securities
Assets
Securities available for sale	13,507	13,138
Level 1
Assets
Securities available for sale	535	519
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Level 1 \| Interest rate lock commitments
Assets
Derivative assets	0	0
Level 1 \| Forward commitments
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Level 2
Assets
Securities available for sale	1,563,995	1,575,030
Derivative assets	5,689	2,237
Liabilities
Derivative liabilities	19,148	8,401
Level 2 \| Interest rate lock commitments
Assets
Derivative assets	0	0
Level 2 \| Forward commitments
Assets
Derivative assets	469	523
Liabilities
Derivative liabilities	2,502	315
Level 3
Assets
Securities available for sale	2,062	2,885
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Level 3 \| Interest rate lock commitments
Assets
Derivative assets	6,864	3,168
Level 3 \| Forward commitments
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Level 3 \| Corporate debt securities
Assets
Securities available for sale	330	846
Recurring Basis
Assets
Total assets at fair value	1,579,614	1,584,362
Liabilities
Total liabilities at fair value	21,650	8,716
Recurring Basis \| Derivative financial instruments
Assets
Derivative assets	5,689	2,237
Liabilities
Derivative liabilities	19,148	8,401
Recurring Basis \| Interest rate lock commitments
Assets
Derivative assets	6,864	3,168
Recurring Basis \| Forward commitments
Assets
Derivative assets	469	523
Liabilities
Derivative liabilities	2,502	315
Recurring Basis \| U.S. government corporations and agencies
Assets
Securities available for sale	5,101	25,766
Recurring Basis \| Mortgage-backed securities
Assets
Securities available for sale	1,220,732	1,242,702
Recurring Basis \| Obligations of states and political subdivisions
Assets
Securities available for sale	326,422	295,982
Recurring Basis \| Corporate debt securities
Assets
Securities available for sale	830	846
Recurring Basis \| Equity securities
Assets
Securities available for sale	13,507	13,138
Recurring Basis \| Level 1
Assets
Total assets at fair value	535	519
Liabilities
Total liabilities at fair value	0	0
Recurring Basis \| Level 1 \| Derivative financial instruments
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis \| Level 1 \| Interest rate lock commitments
Assets
Derivative assets	0	0
Recurring Basis \| Level 1 \| Forward commitments
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis \| Level 1 \| U.S. government corporations and agencies
Assets
Securities available for sale	535	519
Recurring Basis \| Level 1 \| Mortgage-backed securities
Assets
Securities available for sale	0	0
Recurring Basis \| Level 1 \| Obligations of states and political subdivisions
Assets
Securities available for sale	0	0
Recurring Basis \| Level 1 \| Corporate debt securities
Assets
Securities available for sale	0	0
Recurring Basis \| Level 1 \| Equity securities
Assets
Securities available for sale	0	0
Recurring Basis \| Level 2
Assets
Total assets at fair value	1,570,153	1,577,790
Liabilities
Total liabilities at fair value	21,650	8,716
Recurring Basis \| Level 2 \| Derivative financial instruments
Assets
Derivative assets	5,689	2,237
Liabilities
Derivative liabilities	19,148	8,401
Recurring Basis \| Level 2 \| Interest rate lock commitments
Assets
Derivative assets	0	0
Recurring Basis \| Level 2 \| Forward commitments
Assets
Derivative assets	469	523
Liabilities
Derivative liabilities	2,502	315
Recurring Basis \| Level 2 \| U.S. government corporations and agencies
Assets
Securities available for sale	4,566	25,247
Recurring Basis \| Level 2 \| Mortgage-backed securities
Assets
Securities available for sale	1,219,000	1,240,663
Recurring Basis \| Level 2 \| Obligations of states and political subdivisions
Assets
Securities available for sale	326,422	295,982
Recurring Basis \| Level 2 \| Corporate debt securities
Assets
Securities available for sale	500	0
Recurring Basis \| Level 2 \| Equity securities
Assets
Securities available for sale	13,507	13,138
Recurring Basis \| Level 3
Assets
Total assets at fair value	8,926	6,053
Liabilities
Total liabilities at fair value	0	0
Recurring Basis \| Level 3 \| Derivative financial instruments
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis \| Level 3 \| Interest rate lock commitments
Assets
Derivative assets	6,864	3,168
Recurring Basis \| Level 3 \| Forward commitments
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis \| Level 3 \| U.S. government corporations and agencies
Assets
Securities available for sale	0	0
Recurring Basis \| Level 3 \| Mortgage-backed securities
Assets
Securities available for sale	1,732	2,039
Recurring Basis \| Level 3 \| Obligations of states and political subdivisions
Assets
Securities available for sale	0	0
Recurring Basis \| Level 3 \| Corporate debt securities
Assets
Securities available for sale	330	846
Recurring Basis \| Level 3 \| Equity securities
Assets
Securities available for sale	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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