Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount									275,194	49,795	0
Net income	$ 34,802	$ 21,482	$ 36,624	$ 37,333	$ 9,638	$ 27,066	$ 22,638	$ 30,046	$ 130,241	$ 89,388	$ 101,931
Basic weighted average shares	196,516,632	196,445,684	196,270,119	196,217,311	196,173,169	196,062,348	195,747,954	195,745,670	196,363,084	195,933,800	195,735,309
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements									2,985,662	2,113,653	2,117,623
Diluted weighted average shares	199,446,875	199,452,308	198,441,315	198,160,465	198,076,031	198,254,808	197,709,082	197,773,850	199,348,746	198,047,453	197,852,932
Basic net income per share	$ 0.18	$ 0.11	$ 0.19	$ 0.19	$ 0.05	$ 0.14	$ 0.12	$ 0.15	$ 0.66	$ 0.46	$ 0.52
Diluted net income per share	$ 0.17	$ 0.11	$ 0.18	$ 0.19	$ 0.05	$ 0.14	$ 0.11	$ 0.15	$ 0.65	$ 0.45	$ 0.52