Fair value measurements Fair Value Measurements on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2014	Dec. 31, 2013
Fair value measurements on a recurring and nonrecurring basis
Available-for-sale investment securities, at fair value	$ 550,394	$ 529,007
Mortgage-related securities-FNMA, FHLMC and GNMA
Fair value measurements on a recurring and nonrecurring basis
Available-for-sale investment securities, at fair value	430,834	369,444
U.S. Treasury and federal agency obligations
Fair value measurements on a recurring and nonrecurring basis
Available-for-sale investment securities, at fair value	119,560
Municipal bonds
Fair value measurements on a recurring and nonrecurring basis
Available-for-sale investment securities, at fair value		78,590
Fair value measurements on a recurring basis \| Level 1
Fair value measurements on a recurring and nonrecurring basis
Derivative assets		98
Derivative liabilities	71
Fair value measurements on a recurring basis \| Level 1 \| Interest Rate Lock Commitments
Fair value measurements on a recurring and nonrecurring basis
Derivative assets		0
Derivative liabilities	0
Fair value measurements on a recurring basis \| Level 1 \| Forward Contracts
Fair value measurements on a recurring and nonrecurring basis
Derivative assets		98
Derivative liabilities	71
Fair value measurements on a recurring basis \| Level 2
Fair value measurements on a recurring and nonrecurring basis
Derivative assets	398	531
Derivative liabilities	43	26
Fair value measurements on a recurring basis \| Level 2 \| Interest Rate Lock Commitments
Fair value measurements on a recurring and nonrecurring basis
Derivative assets	393	488
Derivative liabilities	3	24
Fair value measurements on a recurring basis \| Level 2 \| Forward Contracts
Fair value measurements on a recurring and nonrecurring basis
Derivative assets	5	43
Derivative liabilities	40	2
Fair value measurements on a recurring basis \| Level 2 \| Bank
Fair value measurements on a recurring and nonrecurring basis
Available-for-sale investment securities, at fair value	550,394	529,007
Fair value measurements on a recurring basis \| Level 2 \| Bank \| Mortgage-related securities-FNMA, FHLMC and GNMA
Fair value measurements on a recurring and nonrecurring basis
Available-for-sale investment securities, at fair value	430,834	369,444
Fair value measurements on a recurring basis \| Level 2 \| Bank \| U.S. Treasury and federal agency obligations
Fair value measurements on a recurring and nonrecurring basis
Available-for-sale investment securities, at fair value	119,560	80,973
Fair value measurements on a recurring basis \| Level 2 \| Bank \| Municipal bonds
Fair value measurements on a recurring and nonrecurring basis
Available-for-sale investment securities, at fair value	0	78,590
Fair value measurements on a recurring basis \| Level 2 \| Other
Fair value measurements on a recurring and nonrecurring basis
Money market funds	$ 10	$ 10

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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