Consolidated Statement of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	COMMON STOCK	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME
TOTAL EQUITY BALANCE at Dec. 31, 2012	$ 525,760
STOCKHOLDERS' EQUITY BALANCE at Dec. 31, 2012	503,936	45,175	458,669	92
Increase (Decrease) in Stockholders' Equity
Net income	22,117		22,117
Other comprehensive loss, net of tax	(124)			(124)
Common stock dividends (per share $0.03)	(1,390)		(1,390)
Stock-based compensation	15,581	513	15,068
TOTAL EQUITY BALANCE at Mar. 31, 2013	556,749
STOCKHOLDERS' EQUITY BALANCE at Mar. 31, 2013	540,120	45,688	494,464	(32)
NONCONTROLLING INTEREST at Mar. 31, 2013	$ 16,629