Bank segment (Details 4) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Available-for-sale securities
Total available-for-sale securities, Amortized cost	$ 549,845	$ 535,090
Gross unrealized gains	7,418	6,911
Gross unrealized losses	(7,942)	(12,994)
Available-for-sale securities	549,321	529,007
Available-for-sale Securities, Continuous Unrealized Loss Position
Fair value, less than 12 months	87,671	313,800
Gross unrealized losses, less than 12 months	(522)	(11,353)
Fair value, 12 months or longer	183,592	19,655
Gross unrealized losses, 12 months or longer	(7,420)	(1,641)
Federal agency obligations
Available-for-sale securities
Total available-for-sale securities, Amortized cost	102,472	83,193
Gross unrealized gains	889	174
Gross unrealized losses	(1,332)	(2,394)
Available-for-sale securities	102,029	80,973
Available-for-sale Securities, Continuous Unrealized Loss Position
Fair value, less than 12 months	14,950	70,779
Gross unrealized losses, less than 12 months	(79)	(2,394)
Fair value, 12 months or longer	29,443	0
Gross unrealized losses, 12 months or longer	(1,253)	0
Mortgage-related securities - FNMA, FHLMC and GNMA
Available-for-sale securities
Total available-for-sale securities, Amortized cost	447,373	374,993
Gross unrealized gains	6,529	4,911
Gross unrealized losses	(6,610)	(10,460)
Available-for-sale securities	447,292	369,444
Available-for-sale Securities, Continuous Unrealized Loss Position
Fair value, less than 12 months	72,721	228,543
Gross unrealized losses, less than 12 months	(443)	(8,819)
Fair value, 12 months or longer	154,149	19,655
Gross unrealized losses, 12 months or longer	(6,167)	(1,641)
Municipal bonds
Available-for-sale securities
Total available-for-sale securities, Amortized cost	0	76,904
Gross unrealized gains	0	1,826
Gross unrealized losses	0	(140)
Available-for-sale securities	0	78,590
Available-for-sale Securities, Continuous Unrealized Loss Position
Fair value, less than 12 months	0	14,478
Gross unrealized losses, less than 12 months	0	(140)
Fair value, 12 months or longer	0	0
Gross unrealized losses, 12 months or longer	$ 0	$ 0