Summary of Operations and Significant Accounting Policies (Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share [Abstract]
Options and share outstanding									2	2	2
Earnings Per Share Reconciliation [Abstract]
Weighted average number of common shares outstanding used in computing basic earnings per share									46,363,000	45,780,000	45,202,000
Net income attributable to common stockholders	$ 6,204	$ 13,619	$ 8,635	$ (1,926)	$ 4,075	$ 8,553	$ 6,653	$ 4,871	$ 26,532	$ 24,152	$ 50,737
Basic earnings per share attributable to common stockholders	$ 0.13	$ 0.29	$ 0.19	$ (0.04)	$ 0.09	$ 0.19	$ 0.15	$ 0.11	$ 0.57	$ 0.53	$ 1.12