Segment Reporting (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Assets
Total assets for reportable segments	$ 2,974,056	$ 2,963,130	$ 3,000,389
Cash and cash equivalents	125,440	175,012	66,118	22,782
Short term investments	999	20,254	0
Other assets	120,906	106,045	91,020
TOTAL ASSETS	$ 3,221,401	$ 3,264,441	$ 3,157,527