CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Comprehensive income:
Net income	$ 59,468	$ 49,951	$ 51,006
Derivative instruments:
Reclassification of losses to net income, net of tax of $51, $51 and $51, respectively.	76	77	76
Other comprehensive income	76	77	76
Comprehensive income	$ 59,544	$ 50,028	$ 51,082