Statements of Changes in Shareholders' Equity (USD $) In Thousands	Total	Common Stock Amount	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income
Beginning Balance at Dec. 31, 2011	$ 2,080,188	$ 77	$ 1,904,748	$ 2,041	$ 173,322
Issuance of common stock	570,589	21	570,568
Share based compensation expense	854		854
Dividends declared on common stock	(158,156)			(158,156)
Net income	158,448			158,448
Other comprehensive income	40,338				40,338
Ending Balance at Jun. 30, 2012	$ 2,692,261	$ 98	$ 2,476,170	$ 2,333	$ 213,660