Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 172,129	$ 40,582	$ 66,053
Other comprehensive income before tax and net of reclassification adjustments:
Change in fair value of interest rate swaps			235
Change in fair value of available-for-sale securities	469	32	19
Other comprehensive income, before tax	469	32	254
Income tax expense related to components of other comprehensive income	183	13	99
Other comprehensive income, net of tax	286	19	155
Comprehensive income	$ 172,415	$ 40,601	$ 66,208