Condensed Financial Statements of Parent Company (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income:
Income before provision for income taxes	$ 74,574	$ 45,160	$ 33,357
Applicable income tax benefit	(25,355)	(15,128)	(10,762)
Net income	49,219	30,032	22,595
Preferred stock dividends	1,354
Net income available to common shareholders	47,865	30,032	22,595
Parent company
Income:
Dividends from subsidiaries	18,135	33,669	9,514
Operating income (loss)	223	59	(52)
Total income	18,358	33,728	9,462
Operating expenses	7,294	2,482	2,331
Income before provision for income taxes	11,064	31,246	7,131
Applicable income tax benefit	2,360	812	769
Equity in undistributed earnings of subsidiary (excess distribution)	35,795	(2,026)	14,696
Net income	49,219	30,032	22,595
Preferred stock dividends	1,354
Net income available to common shareholders	$ 47,865	$ 30,032	$ 22,595