Segment Disclosures - Schedule of Revenue from External Customers (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenue	$ 164,412	$ 187,102	$ 185,042	$ 213,866	$ 157,022	$ 180,269	$ 177,466	$ 204,726	$ 750,422	$ 719,483	$ 677,171
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenue									748,971	717,865	675,467
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenue									$ 1,451	$ 1,618	$ 1,704